Notice of 2018 Annual Meeting

of Stockholders

and Proxy Statement

Harsco Corporation

350 Poplar Church Road

Camp Hill, PA 17011 USA

Invitation to Attend 2018 Annual Meeting of Stockholders

Tuesday, April 24, 2018

9:00 a.m., Eastern Time

Hilton Harrisburg, One North Second Street, Harrisburg, Pennsylvania

Dear Fellow Stockholders:

You are cordially invited to attend the 2018 Annual Meeting of Stockholders (the “Annual Meeting”) of Harsco Corporation (the “Company”), which will be held on Tuesday, April 24, 2018, beginning at 9:00 a.m., Eastern Time, at the Hilton Harrisburg, One North Second Street, Harrisburg, Pennsylvania.

Information about the business to be conducted at the Annual Meeting, including a listing and discussion of the various matters on which you will be asked to act, can be found in the attached Notice of 2018 Annual Meeting of Stockholders and Proxy Statement.

Your vote is very important to us, and I encourage you to vote your shares whether or not you plan to attend the Annual Meeting. There are several ways in which you can vote your shares, including via the Internet, by telephone, or by signing, dating and returning your Proxy Card. Specific information about each of these voting methods can be found in the Proxy Statement under the heading “Questions and Answers About the Company’s Annual Meeting.”

I hope you will be able to attend this year’s Annual Meeting, and I look forward to greeting as many of you as possible. On behalf of my fellow members of the Board of Directors, I want to thank you in advance for voting and for your continued support of the Company.

March 14, 2018

TABLE OF CONTENTS

i

TABLE OF CONTENTS

(continued)

ii

350 Poplar Church Road

Camp Hill, PA 17011 USA

Notice of 2018 Annual Meeting of Stockholders

Tuesday, April 24, 2018

9:00 a.m., Eastern Time

Hilton Harrisburg, One North Second Street, Harrisburg, Pennsylvania

The 2018 Annual Meeting of Stockholders (the “Annual Meeting”) of Harsco Corporation (the “Company”) will be held on Tuesday, April 24, 2018, beginning at 9:00 a.m., Eastern Time, at the Hilton Harrisburg, One North Second Street, Harrisburg, Pennsylvania. The purposes of the meeting are as follows:

The Proxy Statement accompanying this Notice of 2018 Annual Meeting of Stockholders describes each of these items in detail. The Proxy Statement contains other important information that you should read and consider before you vote.

The Board of Directors of the Company has fixed the close of business on March 1, 2018 as the record date for the determination of stockholders who are entitled to notice of, and to vote at, the Annual Meeting and any adjournment or postponement thereof.

The Company is furnishing proxy materials over the Internet as permitted under the rules of the Securities and Exchange Commission. Under these rules, many of the Company’s stockholders will receive a Notice of Internet Availability of Proxy Materials instead of a paper copy of the Notice of 2018 Annual Meeting of Stockholders and Proxy Statement, our Proxy Card, our Annual Report on Form 10-K and the Letter from our CEO. We believe this process allows us to provide our stockholders with the information they need while lowering the costs of printing and distributing proxy materials. Stockholders who do not receive a Notice of Internet Availability of Proxy Materials will receive a paper copy of the proxy materials by mail.

Your vote is very important to us, and we encourage you to vote your shares as soon as possible even if you plan to attend the Annual Meeting in person. Information about how to vote your shares via the Internet, by telephone, or by signing, dating and returning your Proxy Card can be found in the enclosed Proxy Statement.

By order of the Board of Directors,

Russell C. Hochman

Senior Vice President and General Counsel, Chief Compliance Officer & Corporate Secretary

March 14, 2018

Important Notice Regarding the Availability of Proxy Materials for the Stockholder Meeting to be Held on April 24, 2018. The Notice of 2018 Annual Meeting of Stockholders and Proxy Statement, our Proxy Card, our Annual Report on Form 10-K and the Letter from our CEO are available free of charge at www.envisionreports.com/hsc (for registered stockholders) or www.edocumentview.com/hsc (for all other stockholders), or by calling toll-free (866) 641-4276.

1

350 Poplar Church Road

Camp Hill, PA 17011 USA

Proxy Summary

2018 ANNUAL MEETING OF STOCKHOLDERS

VOTING MATTERS AND BOARD RECOMMENDATIONS

This Proxy Summary contains highlights of certain information in this Proxy Statement. Because it is only a summary, it does not contain all the information that you may wish to consider prior to voting. Please review the complete Proxy Statement and the Company’s Annual Report on Form 10-K for additional information.

2

OUR DIRECTOR NOMINEES

You have the opportunity to vote on the election of the following eight nominees for Director. Additional information regarding each Director nominee’s experience, skills and qualifications to serve as a member of the Company’s Board of Directors can be found in the section entitled “Nominees for Director.”

3

GOVERNANCE HIGHLIGHTS

4

EXECUTIVE COMPENSATION HIGHLIGHTS

Our executive compensation program is intended to provide competitive compensation based on performance and contributions to the Company, to incentivize, attract and retain key executives, to align the interests of our key executives with the interests of stockholders, and to drive long-term stockholder value. To achieve these objectives, our executive compensation program includes the following key features:

5

350 Poplar Church Road

Camp Hill, PA 17011 USA

Proxy Statement

This Proxy Statement and the accompanying form of proxy are being furnished in connection with the solicitation of proxies on behalf of the Board of Directors (the “Board”) of Harsco Corporation (the “Company,” “Harsco,” “we” or “us”) for use at the Annual Meeting of Stockholders of the Company (the “Annual Meeting”) to be held at the Hilton Harrisburg, One North Second Street, Harrisburg, Pennsylvania, on Tuesday, April 24, 2018, beginning at 9:00 a.m., Eastern Time.

Should you wish to obtain directions to the Hilton Harrisburg in order to attend the Annual Meeting and vote in person, contact our Corporate Communications Department by calling (717) 763-7064.

The Notice of 2018 Annual Meeting of Stockholders and Proxy Statement, our Proxy Card, our Annual Report on Form 10-K and the Letter from our CEO are available free of charge at www.envisionreports.com/hsc (for registered stockholders) or www.edocumentview.com/hsc (for all other stockholders), by calling toll-free (866) 641-4276.

QUESTIONS AND ANSWERS ABOUT THE COMPANY’S ANNUAL MEETING

6

Please see the Notice of Internet Availability of Proxy Materials or the information your bank, broker or other holder of record provided you for more information on these voting options.

If you do not instruct the Trustee how to vote your shares, the Trustee will vote them in the same proportion as those shares for which the Trustee did receive voting instructions.

7

In certain circumstances, a stockholder will be considered to be present at the Annual Meeting for quorum purposes but will not be deemed to have cast a vote on each particular proposal. This occurs when a stockholder withholds a vote or abstains from voting on a proposal, or in the event of a broker non-vote. In accordance with Delaware law and our Restated Certificate of Incorporation and by-laws, broker non-votes will not be treated as votes cast with respect to the election of Directors (Proposal No. 1) and therefore will not affect the outcome of Director elections. With respect to the advisory vote to approve the compensation of our named executive officers (Proposal No. 3), abstentions will have the effect of negative votes, but broker non-votes will not have any effect. With respect to the ratification of our auditors (Proposal No. 2), abstentions will have the effect of negative votes.

The individuals appointed by the Board to serve as proxies for the Annual Meeting will vote your shares in accordance with the instructions you provide on your proxy card or through your Internet or telephonic vote. If you submit a proxy but do not indicate how your shares should be voted on a particular matter, your shares will be voted as follows:

8

THE BOARD OF DIRECTORS

General Oversight

The Board has general oversight responsibility for the Company’s affairs. Although the Board does not have responsibility for day-to-day management of the Company, Board members stay informed about the Company’s business through regular meetings, site visits and other periodic interactions with management. The Board is deeply involved in the strategic planning process for the Company and each of its business divisions. The Board also plays an important oversight role in the Company’s leadership development and succession planning processes.

Composition

The Board is currently comprised of ten Directors, nine of whom qualify as independent. Stuart E. Graham and Terry D. Growcock will be retiring from the Board immediately prior to the Annual Meeting in accordance with the Board’s retirement policy in the Corporate Governance Principles, and the Board’s size will decrease from ten to eight members in accordance with the Company’s by-laws.

In accordance with the Board’s Corporate Governance Principles and applicable sections of the NYSE Listed Company Manual (the “NYSE Rules”), the independent Directors regularly meet in executive session. These meetings allow the independent Directors to discuss important issues, including the business and affairs of the Company as well as matters concerning management, without any member of management present. During the 2017 fiscal year, the independent Directors held six meetings. On average, the group of independent Directors attended 98% of the independent Directors’ meetings held in 2017.

Leadership Structure

The Company’s governance documents provide the Board with flexibility to select the leadership structure that is most appropriate for the Company and its stockholders. The Board regularly evaluates the Company’s leadership structure and has concluded that the Company and its stockholders are best served by not having a formal policy regarding whether the same individual should serve as both Chairman of the Board and CEO. This approach allows the Board to elect the most qualified Director as Chairman of the Board while also maintaining the ability to separate the Chairman of the Board and CEO roles when necessary or appropriate. For example, as of September 10, 2012, we separated the positions of Chairman of the Board and CEO in light of the fact that our then-recently elected CEO was both new to the Company and had not previously served on a public company board of directors. Prior to this separation the positions of Chairman of the Board and CEO were combined. Currently, F. Nicholas Grasberger III serves as our President & CEO, a position he has held since August 1, 2014. In this role, Mr. Grasberger is responsible for managing the day-to-day operations of the Company and for planning, formulating and coordinating the development and execution of our corporate strategy, policies, goals and objectives. David C. Everitt currently serves as the Non-Executive Chairman of the Board.

In the event the Board determines that the same individual should serve as both Chairman of the Board and CEO, the Board will establish an independent Lead Director position. The individual serving as Lead Director will be selected by the independent Directors and will have responsibilities similar to those of the Non-Executive Chairman of the Board. The Board’s Corporate Governance Principles currently indicate the responsibilities of an independent Lead Director if the position was established.

9

Finally, the Board has established three standing committees to assist with its oversight responsibilities: (1) the Audit Committee; (2) the Management Development and Compensation Committee (the “MD&C Committee”); and (3) the Nominating and Corporate Governance Committee (the “Nominating Committee”). Each of the Audit Committee, MD&C Committee and Nominating Committee is comprised entirely of independent Directors.

Board Role in Risk Oversight

Management is responsible for identifying, evaluating, managing and mitigating the Company’s exposure to risk. It is the Board’s responsibility to oversee the Company’s risk management process and to ensure that management is taking appropriate action to identify, manage and mitigate key risks. The Board administers its risk oversight responsibilities both through active review and discussion of key risks facing the Company and by delegating certain risk oversight responsibilities to committees for further consideration and evaluation. The following table summarizes the role of the Board and each of its committees in overseeing risk:

* Further detail regarding the MD&C Committee’s review of compensation-related risks can be found under the heading “Compensation Policies and Practices as They Relate to Risk Management” of this Proxy Statement.

10

The decision to administer the Board’s oversight responsibilities in this manner has a key effect on the Board’s leadership and committee structure, described in more detail above.

Experiences, Skills and Qualifications

The Nominating Committee works with the full Board to determine the appropriate characteristics, skills and experiences for the Board as a whole as well as its individual members. While the Nominating Committee has not established minimum criteria for Director candidates, it has established important factors that it considers when evaluating potential candidates. These factors are set forth in the Board’s Corporate Governance Principles and include integrity and strength of character, mature judgment, strategic thinking, demonstrated leadership skills, relevant business experience, experience with international business issues and risk, public company experience, innovation, technology or information technology expertise, brand marketing experience, availability, career specialization, relevant technical skills, time and willingness to perform duties as a Director, absence of conflicts of interest, diversity and the extent to which the candidate would fill a present need on the Board. In addition, as explained in more detail below in the section entitled “Diversity,” the Board is committed to a policy of inclusiveness that requires all new Board nominees to be drawn from a pool that includes diverse candidates, with a commitment to seeking out highly qualified women and minority candidates.

In addition to evaluating new Director candidates, the Nominating Committee regularly assesses the composition of the Board in order to ensure it reflects an appropriate balance of knowledge, skills, expertise, diversity and independence. As part of this assessment, each Director is asked to identify and assess the particular experiences, skills and other attributes that qualify him or her to serve as a member of the Board. Based on the most recent assessment of the Board’s composition completed in February 2018, the Nominating Committee and the Board have determined that, in light of the Company’s current business structure and strategies, the Board has an appropriate mix of Director experiences, skills, qualifications and backgrounds.

Set forth below is a general description of the types of experiences and skills the Nominating Committee and the Board believe to be particularly relevant to the Company at this time:

11

A description of the most relevant experiences, skills, attributes and qualifications that qualify each Director and Director candidate to serve as a member of the Board is included in his or her biography.

Diversity

The Board believes that diversity is one of many important considerations in board composition. To ensure the Board is comprised of members with an appropriate mix of characteristics, skills, experiences and backgrounds, the Board has adopted a Board diversity policy, which is set forth in the Board’s Corporate Governance Principles as well as the Nominating Committee’s written charter. Pursuant to the diversity policy, the Board is committed to seeking out highly qualified women and minority candidates as well as candidates with diverse backgrounds, experiences and skills as part of each Board search the Company undertakes, and to ensuring that Board nominees are drawn from a pool that includes diverse candidates, including women and minority candidates.

As noted above, the Nominating Committee evaluates the current composition of the Board from time-to-time to ensure that the Directors reflect a diverse mix of skills, experiences, backgrounds and opinions. Depending on the current composition of the Board, the Nominating Committee may weigh certain factors, including those relating to diversity, more or less heavily when evaluating potential Director candidates.

The Board and the Nominating Committee believe that the Company’s current Directors, as a group, reflect the diverse mix of skills, experiences, backgrounds and opinions necessary to foster an effective decision-making environment and promote the Company’s culture across the globe. Each of the Company’s current Directors has significant experience working in international environments (including Directors who have lived and worked outside the United States for significant portions of their careers), and Board member experiences cover a wide range of industries, including manufacturing, rail, accounting, consulting, consumer products, industrial services and education.

12

PROPOSAL 1: ELECTION OF DIRECTORS

The first proposal to be voted on at the Annual Meeting is the election of eight Directors, each of whom has been recommended for election by the Board. S. E. Graham and T. D. Growcock will be retiring from the Board immediately prior to the Annual Meeting in accordance with the Board’s retirement policy in the Corporate Governance Principles, and the Board’s size will decrease from ten to eight members in accordance with the Company’s by-laws. If elected, the Directors will hold office until the next annual meeting of stockholders or until their successors are elected and qualified, subject to the Board’s resignation requirement (as described in more detail below).

The Board recommends that stockholders vote “FOR” the election of each of the following nominees:

As discussed above, under the Company’s Restated Certificate of Incorporation, in any uncontested election, each Director nominee must receive the affirmative vote of a majority of the votes cast with respect to his or her election in order to be elected. This is known as a “majority voting standard.” If any Director nominee fails to receive more “for” votes than votes “against” for his or her election, then such Director will be required by the Company’s by-laws to tender his or her resignation to the Board for consideration. The Nominating Committee will then review the resignation and recommend to the Board whether to accept or reject it. The Board will act on the Nominating Committee’s recommendation and publicly disclose its decision within 90 days following certification of the election results. In the event the Board determines not to accept the Director’s resignation, the Board will also disclose the reasons such resignation was rejected. The Director who tendered his or her resignation will not participate in the Nominating Committee’s recommendation or the Board’s decision.

If a Director’s resignation is not accepted by the Board, then the Director who tendered that resignation will continue to serve on the Board until the 2019 Annual Meeting of Stockholders and until his or her successor is elected and qualified, or until his or her earlier death, unconditional resignation or removal.

Nominees for Director

All of the following Directors have been recommended for election by the Nominating Committee, and the Board has approved all such recommendations. Two current Directors, S. E. Graham and T. D. Growcock, are not being nominated for election because each of them will be retiring from the Board immediately prior to the Annual Meeting in accordance with the Board’s retirement policy in the Corporate Governance Principles. Each of the following nominees for Director has accepted the nomination and has agreed to serve as a Director if elected by the Company’s stockholders.

13

The information set forth below states the name of each nominee for Director standing for re-election, his or her age (as of March 1, 2018), a listing of present and recent employment positions, the year in which he or she first became a Director of the Company, other directorships held, the nominee’s specific experience, qualifications, attributes or skills that qualify him or her to serve as a Director and the committees of the Board on which the individual serves.

14

15

16

17

MEETINGS AND COMMITTEES OF THE BOARD

Meetings of the Board and Director Attendance at Annual Meeting

The Board held six meetings during the fiscal year ended December 31, 2017. Each Director attended at least 75% of the aggregate number of Board and applicable committee meetings held during the period of 2017 for which he or she served as a Director.

It is our policy to request that all Board members attend annual stockholder meetings. However, we also recognize that personal attendance by all Directors is not always possible. All Directors that served on the Board at the time of the Annual Meeting of Stockholders in 2017 attended the Annual Meeting of Stockholders in 2017.

Committees of the Board

The Board has established standing Audit, Management Development and Compensation, and Nominating and Corporate Governance committees. Membership in each of these committees, as of March 1, 2018, is shown in the following chart:

All Directors listed above, including committee chairs, served on the respective committees listed above for the entire 2017 fiscal year, except as follows:

The table below identifies the number of meetings held by each committee in 2017, provides a brief description of the duties and responsibilities of each committee, and provides general information regarding the location of each committee’s charter:

18

19

20

CORPORATE GOVERNANCE

We have a long-standing commitment to good corporate governance practices. These practices come in many different forms and apply at all levels of our organization. They provide the Board and our senior management with a framework that defines responsibilities, sets high standards of professional and personal conduct and promotes compliance with our various financial, ethical, legal and other obligations and responsibilities.

Corporate Governance Principles

The Board has adopted Corporate Governance Principles that, along with the charters of the Board committees, provide the framework for our Board’s operation and governance. The Nominating Committee is responsible for overseeing and reviewing our Corporate Governance Principles at least annually and recommending any proposed changes to the Board for approval. The Corporate Governance Principles are available on our website at www.harsco.com/about-us in the Corporate Governance section.

Code of Conduct

We have adopted a Code of Conduct applicable to our Directors, officers and employees worldwide. The Code of Conduct is issued in booklet form and an online training program facilitates new employee orientation and individual refresher training. Our Code of Conduct is produced in over 20 languages. The Code of Conduct, including amendments thereto or waivers thereof granted to a Director or executive officer, if any, can be viewed on our website at www.harsco.com/about-us in the Corporate Governance section.

Stockholder and Interested Party Communications with Directors

The Board has established a formal process for stockholders and interested parties to communicate directly with the Non-Executive Chairman, the non-management Directors or with any individual member of the Board. Stockholders and interested parties may contact any member of the Board by writing to the specific Board member in care of our Corporate Secretary at our Corporate Headquarters (350 Poplar Church Road, Camp Hill, PA 17011). Our Corporate Secretary will forward any such correspondence to the applicable Board member; provided, however, that any such correspondence that is considered by our Corporate Secretary to be improper for submission to the intended recipients will not be provided to such Directors. In addition, Board members, including the Non-Executive Chairman, can be contacted by e-mail at BoardofDirectors@harsco.com.

Director Independence

The Board has affirmatively determined that the following nine Directors are independent pursuant to the applicable independence requirements set forth in the NYSE Rules and by the SEC because they either have no relationship with the Company (other than as a Director and stockholder) or because any relationship they have with the Company is immaterial: Messrs. Earl, Everitt, Graham, Growcock, Longhi, Purvis and Widman and Ms. Eddy and Ms. La Roche. In making these independence determinations, the Board, in consultation with the Nominating Committee, reviewed the direct and indirect relationships between each Director and the Company and its subsidiaries, as well as the compensation and other payments each Director received from or made to the Company and its subsidiaries.

Nominations of Directors

The Nominating Committee is responsible for overseeing the selection of qualified nominees to serve as members of the Board. Consistent with the Board diversity policy, in administering its oversight responsibilities, the Nominating Committee is committed to seeking out highly qualified women and minority candidates as well as candidates with diverse backgrounds, experiences and skills as part of each Board search the Company undertakes, and to ensuring that Board nominees are drawn from a pool that includes diverse candidates, including women and minority candidates. Beyond those specific parameters, the Nominating Committee has not

21

adopted formal selection procedures, but instead utilizes general guidelines that allow it to adjust the selection process to best satisfy the objectives established for any Director search. The Nominating Committee considers Director candidates recommended by any reasonable source, including current Directors, management and stockholders. In the case of Mr. Longhi and Mr. Purvis, the Nominating Committee considered the recommendations of a third-party search firm. Pursuant to its charter, the Nominating Committee has the authority to retain search firms to assist it in identifying candidates to serve as Directors and to approve the fees and other retention terms of any such firms.

The Nominating Committee evaluates all Director candidates in the same manner, regardless of the source of the recommendation of such Director candidate.

The Nominating Committee will consider recommendations for Director candidates from stockholders if such recommendations are submitted in writing to:

Corporate Secretary

Harsco Corporation

350 Poplar Church Road

Camp Hill, PA 17011

Any such written recommendation from stockholders must set forth the following information:

22

This information must be submitted as provided under the heading “STOCKHOLDER PROPOSALS AND NOMINATIONS FOR PRESENTATION AT 2019 ANNUAL MEETING OF STOCKHOLDERS.”

There were no material changes to the procedures relating to stockholder nominations during 2017, and there have been no such changes to date in 2018. The Nominating Committee believes that these procedural requirements are intended solely to ensure that it has a sufficient basis on which to assess potential Director candidates and are not intended to discourage or interfere with appropriate stockholder nominations. The Nominating Committee does not believe that any such requirements subject any stockholder or proposed nominee to any unreasonable burden. The Nominating Committee and the Board reserve the right to change the above procedural requirements from time to time and/or to waive some or all of the foregoing requirements with respect to certain nominees, but any such waiver shall not preclude the Nominating Committee from insisting upon compliance with any and all of the above requirements by any other recommending stockholder or proposed nominees.

23

NON-EMPLOYEE DIRECTOR COMPENSATION

The general policy of our Board is that compensation for non-employee Directors should be competitive with similarly situated companies and should be comprised of a mix of cash and equity. Our Nominating Committee annually reviews market data regarding comparable director compensation programs. This data is prepared by management and the independent compensation consultant utilizing several broad board compensation studies completed within one year of the Nominating Committee’s review.

The compensation structure for non-employee Directors for 2017 was as follows:

In addition to the above listed compensation, Directors are reimbursed for reasonable travel expenses related to attendance at Board or committee meetings.

Our Board has instituted a stockholding requirement for Board members equal to five times the annual retainer. Board members have five years from the date they join the Board to comply with this requirement. Vested and unvested Restricted Stock Units (“RSUs”), as well as phantom shares acquired through deferral of Director fees (as described below), are included for purposes of determining compliance with Director stockholding requirements. At December 31, 2017, all of our non-employee Directors who had served for at least five years were in compliance with Director stockholding requirements.

24

Beginning in 2016, RSUs are granted under the new 2016 Non-Employee Directors’ Long-Term Equity Compensation Plan (the “Director Plan”). Each RSU under the Director Plan vests at the close of business on the earlier of (i) the first anniversary of the grant date or (ii) the annual meeting of stockholders in the year immediately following the year of grant, subject to accelerated vesting in full if service as a Director terminates due to death, disability or under a mandatory retirement policy, and subject to pro rata vesting in the event of termination of service in other circumstances. Each RSU will be settled by issuance of a share of our common stock. Dividend equivalents on the RSUs are not paid prior to vesting, but are settled thereafter.

The Deferred Compensation Plan for Non-Employee Directors allows each non-employee Director to defer all or a portion of his or her Director compensation, including RSU grant, until some future date selected by the Director. Pursuant to the Director’s election, the accumulated deferred compensation is held in either an interest-bearing account or a Company phantom share account. The interest-bearing deferred account accumulates notional interest on the account balance at a rate equal to the five-year United States Treasury Note yield rate in effect from time to time. Contributions to the phantom share account are recorded as notional shares of the Company’s Common Stock. Deferred amounts are credited to the Director’s account quarterly on the 15th of February, May, August and November. The number of phantom shares recorded is equal to the number of shares of Common Stock that the deferred compensation would have purchased at the market price of the stock on the day the account is credited. Dividend equivalents are earned on the phantom shares and are credited to the account as additional phantom shares. All phantom shares are non-voting and payments out of the account are made solely in cash, based upon the market price of the Common Stock on the date of payment selected by the Director. Under certain circumstances, the accounts may be paid out early upon termination of directorship following a change in control.

Directors who are actively employed by us receive no additional compensation for serving as Directors, and we do not pay consulting or professional service fees to Directors.

2017 Director Compensation

The table below details the compensation earned by our non-employee Directors for 2017:

25

26

SHARE OWNERSHIP OF DIRECTORS, MANAGEMENT AND CERTAIN BENEFICIAL OWNERS

The following table sets forth information with respect to the beneficial ownership of our outstanding voting securities, stock options and other stock equivalents by: (1) our President & CEO, our CFO, and the other three current executive officers named in the 2017 Summary Compensation Table, whom we refer to collectively as our NEOs; (2) each Director and Director candidate; (3) all current Directors and executive officers as a group; and (4) certain beneficial owners of more than 5% of our Common Stock. All of our outstanding voting securities are Common Stock.

Beneficial ownership information in the table is as of March 1, 2018, except the number of shares beneficially owned by beneficial owners of more than 5% of the Common Stock which is as of the dates stated in footnotes (3) and (4) to the table (percentages are calculated assuming continued beneficial ownership at March 1, 2018).

* Less than one percent.

27

Except as otherwise stated, each individual or entity has sole voting and investment power over the shares set forth opposite his, her or its name. None of the Directors, Director candidates or executive officers individually beneficially owned 1% or more of our Common Stock, and our current Directors and executive officers as a group beneficially owned less than 1% of our outstanding common stock.

REPORT OF THE AUDIT COMMITTEE

The Audit Committee is currently composed of five Directors, each of whom is considered independent under the rules of the NYSE and the SEC. The Board has determined that each of Ms. La Roche, Ms. Eddy, Mr. Growcock and Mr. Widman qualifies as an “audit committee financial expert” as that term is defined under the rules promulgated by the SEC.

The Audit Committee operates pursuant to a written charter that complies with the guidelines established by the NYSE.

The Audit Committee is responsible for monitoring our financial reporting processes and system of internal controls, supervising our internal auditors and overseeing the independence and performance of the independent auditors. In carrying out these responsibilities, the Audit Committee meets with our internal auditors and our independent auditors to review the overall scope and plans for their respective audits of our financial statements. The Audit Committee also meets privately (and in separate meetings) with members of management, our independent auditors and our internal auditors following each Audit Committee meeting and as may otherwise be needed. The Audit Committee meets with management and with the independent auditors each quarter to review and discuss our Annual Report on Form 10-K and quarterly reports on Form 10-Q prior to their being filed with the SEC, and also meets with management and our independent auditors to review and discuss our quarterly earnings prior to their release.

28

The Audit Committee’s responsibility is to monitor and oversee the audit and financial reporting processes. However, the members of the Audit Committee rely, without independent verification, on the information provided to them and on the representations made by management, and the report issued by the independent registered public accounting firm. While the Audit Committee and the Board monitor our financial record keeping and controls, management is ultimately responsible for our financial reporting process, including our system of internal controls, disclosure control procedures and the preparation of the financial statements. The independent auditors support the financial reporting process by performing an audit of our financial statements and issuing a report thereon.

The Audit Committee has reviewed and discussed with management and the independent auditors the audited consolidated financial statements for the year ended December 31, 2017 and related periods. These discussions focused on the quality, not just the acceptability, of the accounting principles used by us, key accounting policies followed in the preparation of the financial statements and the reasonableness of significant judgments made by management in the preparation of the financial statements and alternatives that may be available.

In addition, the Audit Committee has discussed with the independent auditors the matters required to be discussed pursuant to Statement on Auditing Standards No. 16, “Communications with Audit Committees,” as adopted by the Public Company Accounting Oversight Board, including the quality of our accounting principles, the reasonableness of significant judgments and the clarity of disclosures in the financial statements. The Audit Committee has also received the written disclosures and the letter from the independent auditors required by applicable requirements of the Public Company Accounting Oversight Board regarding the independent auditors’ communications with the Audit Committee concerning independence, and has discussed with the independent auditors the independent auditors’ independence.

Based on the review and discussions referred to above, the Audit Committee’s review of the representations of management and the report of the independent auditors, the Audit Committee recommended to the Board that the audited financial statements be included (and the Board approved such inclusion) in our Annual Report on Form 10-K for the fiscal year ended December 31, 2017 for filing with the SEC.

SUBMITTED BY THE AUDIT COMMITTEE:

P. C. Widman, Chairman

K. G. Eddy

T. D. Growcock

E. La Roche

M. Longhi

29

FEES BILLED BY THE INDEPENDENT AUDITORS FOR AUDIT AND NON-AUDIT SERVICES

The following table sets forth the amount of audit fees, audit-related fees, tax fees and all other fees billed or expected to be billed by PricewaterhouseCoopers LLP, our principal auditor for the years ended December 31, 2017 and December 31, 2016.

The Audit Committee has considered the possible effect of non-audit services on the auditors’ independence and pre-approved the type of non-audit services that were rendered. The Audit Committee has adopted a policy authorizing the pre-approval of certain audit, non-audit and tax services (and related fees) to be provided by the independent auditors. The services to be provided are to be reviewed with the Audit Committee and approval is given for a specific dollar amount and for a period of not greater than 12 months. Services that are not pre-approved in this manner must be pre-approved on a case-by-case basis throughout the year. Additionally, if the pre-approved fee is exceeded, the Audit Committee must be advised of such overruns. In making its decision regarding the approval of services, the Audit Committee will consider whether such services are consistent with the SEC’s rules on auditor independence, whether the independent auditor is best positioned to provide such services and whether the services might enhance the Company’s ability to manage or control risk or improve audit quality. No services were provided during the last two fiscal years pursuant to the de minimis safe harbor exception from the pre-approval requirements.

All of the fees included in the table above were pre-approved by the Audit Committee.

30

PROPOSAL 2: RATIFICATION OF APPOINTMENT OF INDEPENDENT AUDITORS

The Audit Committee has appointed PricewaterhouseCoopers LLP as independent auditors to audit our financial statements for the fiscal year ending December 31, 2018. Although not required to do so, the Board has determined to submit the Audit Committee’s appointment of PricewaterhouseCoopers LLP as our independent auditors to stockholders for ratification as a matter of good corporate governance. In the absence of contrary direction from stockholders, all proxies that are submitted will be voted in favor of the ratification of the Audit Committee’s appointment of PricewaterhouseCoopers LLP as our independent auditors.

If this proposal is not ratified by at least a majority of the shares of our outstanding common stock present in person or by proxy and entitled to vote on matters at the Annual Meeting, the appointment of the independent auditors will be reevaluated by the Audit Committee. Due to the difficulty and expense of making any substitution of auditors, it is unlikely that their appointment for the audit of the financial statements for the fiscal year ending December 31, 2018 would be changed. However, the Audit Committee may review whether to seek new independent auditors for the fiscal year ending December 31, 2019.

A representative of PricewaterhouseCoopers LLP will attend the Annual Meeting, with the opportunity to make a statement and answer questions of stockholders.

Required Vote: The ratification of the appointment of PricewaterhouseCoopers LLP as independent auditors will be approved if it receives the approval of at least a majority of the shares represented at the Annual Meeting.

The Board recommends that stockholders vote “FOR” the ratification of the Audit Committee’s appointment of PricewaterhouseCoopers LLP as the Company’s independent auditors for the fiscal year ending December 31, 2018.

31

COMPENSATION DISCUSSION & ANALYSIS

This Compensation Discussion & Analysis (“CD&A”) provides information regarding our executive compensation guiding principles, the elements of our executive compensation program, and the factors that were considered in making compensation decisions for our named executive officers (“NEOs”) for 2017. Our MD&C Committee is responsible for establishing our executive compensation program, including components underlying the philosophy and related policies. The MD&C Committee is charged with aligning the Company’s performance – and resulting impact on stockholder interests – with the compensation actions for both our NEOs and the broader Harsco employee population.

EXECUTIVE SUMMARY

Business Highlights

Harsco management continued to execute strategies in 2017 to further develop and strengthen the Company’s portfolio of businesses, to maintain a strong financial profile and to enable the Company to generate returns above the cost of capital. 2017 also represented the year in which Harsco transitioned towards a broader growth strategy across its businesses. Each Business Unit focused on outpacing relevant market trends supported by a return-based decision making process. The success of strategic initiatives in recent years, along with some uplift in end markets, is illustrated by the increases to our 2017 outlook throughout the year and the year-over-year improvement in certain key performance indicators (“KPIs”).

The Company’s largest business unit, Metals & Minerals (“M&M”), continued to demonstrate improved financial performance for a second consecutive year. This trend further reflects the financial benefits of the transformational actions executed from 2013 to 2016 to build M&M into a leaner, higher-return business through a number of process efficiency initiatives. Additionally, M&M implemented a growth strategy to expand its business relationships with existing and new customers. Recent sales wins prove the benefits of this initiative. Overall, M&M’s 2017 operating income increased meaningfully and continues to generate strong free cash flow.

Our Industrial business unit also realized a sizable improvement in 2017 operating income and margins. These positive trends resulted from an increase in capital spending by U.S. energy customers, which troughed in mid-2016, coupled with new product introductions and significant efficiency initiatives implemented over the past two years. Meanwhile, our Rail business unit demonstrated resilience at the bottom of the North American economic cycle. Growth in its short-cycle, aftermarket and international sales partially offset the domestic revenue pressures, while Rail executed a number of transformational initiatives to improve operational and commercial effectiveness, positioning this business for growth as end markets recover.

Harsco’s stated 2017 objectives included achieving its 2017 Annual Operating Plan; developing and implementing a growth strategy in M&M; pursuing growth through adjacent markets penetration and new products delivery in the Industrial business unit; executing cost and improvement initiatives in the Rail business unit to proactively manage unfavorable economic pressures; and maintaining a strong and appropriate capital structure. The Company made significant progress against these priorities, which are reflected in our 2017 financial results and improved share price. Overall, Harsco’s executive management team was pleased with the strategic and operational progress within the underlying businesses and remains committed to the Company’s strategic initiatives.

A more extensive list of our key accomplishments is noted below:

32

Each of our businesses demonstrated considerable progress against their operating objectives and contributed to the Company’s successes in 2017. Achievements and other notable activities across our business units are summarized in the table below:

The end-markets served by Harsco were stable to improving in 2017, and we expect to benefit as market conditions improve further.

33

Compensation Highlights

Advisory Vote on Named Executive Officer Compensation

Stockholders voted strongly in support of Harsco’s compensation for its NEOs in 2017 with approximately 94% of votes cast in support of Harsco’s say-on-pay proposal.

Program Governance Highlights

We strive to maintain a program that is consistent with market best practices, supportive of our business structure, and aligned with our stockholder’s expectations. The table below presents components of our executive compensation program that align with market best practices.

34

Changes to Compensation Programs

In 2017, the MD&C Committee, management, and the MD&C Committee’s external compensation advisor, Pay Governance LLC (“Pay Governance”), partnered closely to adopt the following changes to the Company’s pay program:

Incentive Plan Results

For 2017, all three business units, M&M, Industrial and Rail, earned an annual incentive payout based on their financial performance as compared against the approved Business Unit Contribution (“BUC”) targets. Harsco BUC consists of two distinct and separate components: 1) operating income (excluding the effect of certain special items as determined by the MD&C Committee) minus; 2) a fixed cost of capital rate applied to planned controllable net assets deployed. Upon consolidation of each business unit’s results including Corporate charges, Harsco Consolidated earned an above target payout. The payout factors related to the results achieved are noted below.

The resulting payouts from the Annual Incentive Plan (“AIP”) along with the base salary earned and the long-term incentives granted in 2017 for the NEOs are presented in the table below.

35

It is important to note that long-term incentives granted in March of 2017 are considered by the MD&C Committee to be a pay opportunity with the realizable value fully dependent on Harsco’s future share price performance. For NEOs, long-term incentives consist of one-third SARs, Restricted Stock Units (“RSUs”) and PSUs.

The Company granted performance share units in 2015 with vesting conditioned generally on Harsco’s TSR performance relative to the S&P MidCap 400 Index for the 3-year period from 2015 through 2017. Harsco’s TSR for the performance period was at the 24^th percentile of the index, resulting in a payout of 0% of target.

Discussion of Chief Executive Officer Pay

We believe our executive compensation program strikes an appropriate balance between our ability to attract, motivate, develop, and retain highly qualified leaders and help to ensure our executives’ interests are parallel with the long-term interests of our stockholders. As such, the majority of executive compensation is structured utilizing equity compensation, aligning the realized value of these awards with stockholders’ interests.

Pay Opportunity versus Realized Pay and Potential Realizable Pay

On an annual basis, the MD&C Committee approves a targeted pay opportunity by establishing the target AIP level and the grant value of long-term incentive awards for the year. However, the potential real value of these awards is highly dependent on: (1) Harsco’s operating performance, as defined by BUC, for the cash AIP award; (2) Harsco’s share price and relative TSR performance for the long-term incentive compensation; and (3) satisfaction of the service obligation in the long-term incentive’s vesting schedules.

Realized Pay

As a large majority of pay opportunity represents potential pay that could be realized in future years, we also review the CEO’s realized pay for each full year. In short, realized pay is comprised of actual pay earned including base salary and AIP payouts plus the value of vested/exercised equity awards during the period. While Mr. Grasberger’s pay opportunity is established to be competitive with median market levels, his realized pay varies based on Harsco’s stock price performance, equity vesting and incentive payouts.

Potential Realizable Pay

In addition to pay opportunity and realized pay, a third perspective the Committee considers is potential realizable pay. Potential realizable pay considers base salary and AIP payouts plus a “snapshot” of the intrinsic value of equity within the period. The intrinsic value of equity uses the December 29, 2017 share price to calculate a “snapshot” value for awards granted within the period. It combines RSUs, “in the money” value of SARs, and an estimate of the value of unvested PSUs based on the relative total stockholder return performance to date.

Realized and Potential Realizable Pay as a Percent of Pay Opportunity

Mr. Grasberger’s realized pay for 2015 to 2017 was 49% of the pay opportunity granted over the same time period due to a combination of mixed results of actual AIP payouts, no PSUs earned, no SARs exercised and standard RSUs vesting. However, Mr. Grasberger’s potential realizable pay is 157% of the pay opportunity granted for the 2015 to 2017 period, primarily due to the Company’s strong TSR performance since 2016 that is driving an increase in the intrinsic value of equity awards above the value on the date of grant.

It is important to note that the intrinsic value of equity awards is based on share price and relative TSR performance of unvested awards for incomplete performance cycles and will change each year. The actual realized value will continue to be determined by the future share price (and, for PSUs, TSR) performance of the Company through the vesting periods.

36

See the illustration below for a detailed presentation of each of these methodologies.

Pay Opportunity: Base salary earned + target AIP + grant date fair value of long-term incentive awards (PSUs + RSUs + SARs) in each fiscal year.

Realized Pay: Base salary earned + actual AIP paid + value of equity vested or exercised in each fiscal year.

Potential Realizable Pay: Base salary earned + actual AIP paid + intrinsic value of PSUs at the currently projected vesting level + the intrinsic value of RSUs and SARs. Intrinsic values were established as of December 29, 2017 using an $18.65 share price.

PSU TSR Performance Assumptions: 2017 potential realizable pay assumes a 178% PSU payout based on the 2017 TSR relative to the S&P 600 Industrial Index. 2016 potential realizable pay assumes a 200% PSU payout based on the 2016 to 2017 TSR relative to the S&P 600 Industrial Index. 2015 potential realizable pay assumes a 0% PSU payout based on the 2015 to 2017 TSR relative to the S&P 400 MidCap Index.

CEO three-year aggregate pay comparison 157% of pay opportunity 49% of pay opportunity $Millions pay opportunity realized pay potential realizable pay base salary AIP PSUs RSUs SARs

37

Potential Realizable Pay versus the Peer Group

When comparing the last three years of pay and total stockholder return to the companies used in our market benchmarking analysis there is reasonable alignment between Harsco’s total stockholder return and the CEO’s potential realizable pay. The trend in potential realizable pay is aligned with total stockholder returns, as the majority of the CEO’s potential realizable value results from performance-based awards granted in the most recent two years where returns are the strongest.

2017 Named Executive Officers

Our NEOs for fiscal 2017 are as follows:

For 2017, the CD&A and the related compensation tables and narratives cover five NEOs and disclose a variety of compensation decisions and actions. Details about the specific arrangements made with our NEOs can be found in the “Employment Arrangements with Certain NEOs” and “Potential Payments upon Change in Control and Other Potential Post-Employment Payments” sections.

Above median performance & below median realizable TDC value Above median performance & above median realizable TDC value Below median performance & below median realizable TDC value Below median performance & above median realizable TDC value ceo potentital realizable pay percent rank

38

DISCUSSION AND ANALYSIS OF 2017 COMPENSATION

Compensation Guiding Principles

The Company has a set of principles that guide our compensation program design with the core assumption that executive compensation is a highly effective business tool when designed, communicated and administered properly. These principles strongly influenced our executive compensation decisions and the implementation of our 2017 program. The objectives set forth by the MD&C Committee and management team will help ensure any future Company compensation program will be designed in accordance with our guiding principles.

39

Key Compensation Practices

Further aligning with our Guiding Principles, the MD&C Committee maintains a clear set of goals for designing and implementing our pay program.

40

Response to Previous Say-on-Pay Advisory Voting

At our 2017 Annual Meeting, stockholders voted strongly in support of Harsco’s NEO compensation programs with 94% of votes cast in support of the Harsco’s say-on-pay proposal.

We believe the continued support demonstrates our commitment to attain the highest levels of stockholder support for our executive compensation program as stockholder input is respected. After strong favorable support the past few years, a formal outreach program on compensation was not conducted. Stockholders were engaged on various other issues throughout 2017 at which time stockholders had the opportunity to provide feedback on a variety of topics if they so wished. The MD&C Committee considers stockholder’s viewpoints in the development and approval of all compensation policies and practices at Harsco.

Key Changes Implemented to Executive Compensation Programs

As previously discussed in the prior year’s Compensation Discussion & Analysis, the MD&C Committee, management, and the MD&C Committee’s external compensation advisor partnered closely to adopt a change in the timing of LTIP grants from May to early March. A first quarter LTIP grant aligns with the timing utilized by our peers and is also consistent with our annual incentive program.

Additionally, effective with the 2018 grant, the PSU payout will be capped at 100% (“target”) if TSR is negative over the measurement period. Previously, payout was set to zero if TSR was negative. The new

41

approach is consistent with the prevailing market practice for companies that cap payouts for negative TSR and balances the incentive to outperform the index by limiting the upside when the share price declines for all LTIP participants. Lastly, the CEO’s mix of PSUs as a percent of his LTIP award was increased from 33% to 40% for 2018 to place more emphasis on performance contingent awards.

Overview of 2017 Compensation Decisions and Actions

Applying our principles and stated compensation practices, the MD&C Committee reviewed each NEO’s compensation package individually with the objective of supporting our business strategies, ensuring market competitiveness, providing incentives to motivate and retain our key executives, and underpinning our succession planning process.

President & CEO

Effective May 1, 2017, the MD&C Committee increased Mr. Grasberger’s base salary by 3%, in recognition of his contributions to the Company including those described in the Business Highlights and consistent with the overall merit increase budget for Harsco in the U.S. His target AIP and LTIP, as a percent of base salary, were left unchanged from 2016. The CEO’s annual base salary and target incentive levels for the past three years are provided below:

Other NEOs

Consistent with the actions approved for the CEO, all other NEOs received a 3% increase in their annual base salaries, effective May 1, 2017, in recognition of their contributions to the Company and consistent with the overall merit increase budget for Harsco in the U.S. No adjustments were made to the incentive targets of any NEOs.

Determining 2017 NEO Compensation

General Process

Executive compensation decisions at the Company are the product of several factors, in each case subject to modification by the MD&C Committee as it may deem necessary in its discretion, and also dependent upon whether the decisions are made in the normal pay setting cycle or under special circumstances for a newly appointed or hired executive. For 2017, the predominant factors influencing pay determinations for our NEOs included:

42

Role of MD&C Committee

For 2017, all members of the MD&C Committee were independent Directors, enabling them to be objective representatives for our stockholders. The MD&C Committee oversaw the design and development of our 2017 NEO compensation program and determined CEO compensation consistent with the overall objectives of the program, as described above. The MD&C Committee also approved all incentive compensation plans and approved or revised recommendations made by the President & CEO for compensation decisions affecting any of the other NEOs.

Role of the President & CEO

Our President & CEO, assisted by our Human Resources department, was responsible for the implementation and administration of the executive compensation program during 2017. Prior to and during 2017, Mr. Grasberger met with the MD&C Committee and Pay Governance to consider and recommend the overall structure for our NEO compensation program, to set and evaluate 2017 AIP metrics, and to make specific recommendations regarding the form and amount of compensation opportunities for the other NEOs. The final decisions regarding the NEOs’ compensation were, however, made by the MD&C Committee. The President & CEO does not play any role with respect to any matter affecting his own compensation.

Role of Compensation Consultants

Independent MD&C Committee Consultant

For 2017, our MD&C Committee engaged Pay Governance to provide independent counsel and advice to the MD&C Committee. Pay Governance provided the following services to the MD&C Committee in 2017:

At the MD&C Committee’s direction during 2017, management provided all MD&C Committee materials to the independent consultant and discussed such materials and any recommendations relating thereto with the consultant in advance of each MD&C Committee meeting. Pay Governance considered and discussed the information with the MD&C Committee chairperson, specifically identifying any issues or concerns. The MD&C Committee considered Pay Governance’s input as part of its decision-making process.

Pay Governance also provided consulting related to non-employee Director compensation directly to the Nominating and Governance Committee.

43

Independence Assessment: No Compensation Consultant Conflicts of Interest

The MD&C Committee assessed the independence of Pay Governance in 2017, as required under NYSE listing rules. The MD&C Committee has also considered and assessed all relevant factors, including but not limited to those set forth in Rule 10C-1(b)(4)(i) through (vi) under the Exchange Act, that could give rise to a potential conflict of interest with respect to the compensation consultant described above. Based on this review, we are not aware of any conflict of interest raised by the work performed by Pay Governance that would prevent the consultant from serving as an independent consultant to the MD&C Committee.

Management Consultants

Our Human Resources department retained Willis Towers Watson during 2017 to provide additional executive compensation support, including assistance with analysis and recommendations regarding short- and long-term incentive planning services because of their broad level of expertise and expansive knowledge of relevant market data in that area. In addition, Willis Towers Watson provided guidance related to the implementation of the CEO Pay Ratio requirements. Our Human Resources department also used various survey data compiled by Willis Towers Watson to provide information to the MD&C Committee as part of its decision-making processes.

In 2017, Willis Towers Watson again provided pension plan-related and other similar advice to our Human Resources and Finance departments as well as measurement support for various casualty exposures. The decision to engage Willis Towers Watson for these non-compensation related services was made by management.

How We Used Market Data for 2017 Pay Decisions

Based on our compensation philosophy, whereby we wish to attract and retain high caliber talent, our first step in establishing pay levels for each of our NEOs is to target compensation initially at or near the median (50^th percentile) of market data for executives in similar positions. In reviewing the 2017 compensation of our NEOs, the MD&C Committee references two sources of market data when making compensation decisions: survey data and peer group data.

All components of the Company’s NEO compensation packages, as well as the aggregate target total compensation (the sum of base salary, target annual incentives, and target long-term incentives) levels for the NEOs, are initially targeted to the 50^th percentile of similarly situated employees of companies in the comparison Compensation Peer Group and relevant survey data. Variation above or below the 50^th percentile results when, in the judgment of the MD&C Committee, the value of the NEO’s experience, performance, scope and/or specific skills, together with his or her ability to impact business results, or other business conditions, justify the variation.

Variation can also result based upon the terms of individually negotiated employment arrangements and year-to-year fluctuations in the peer group data and/or the survey data.

44

Compensation Peer Group

Each year, we review our Compensation Peer Group to ensure our compensation is being benchmarked to comparable companies considering industry, financial and operational similarities. In light of the Company’s lower market cap and revenue since the Compensation Peer Group was initially developed, the MD&C Committee approved changes to this custom peer group to better align with the current size and scope of the consolidated business. Although there are other companies who compete with Harsco’s various business segments, some were not included in the peer set due to their differences in size and scope as compared to Harsco.

As in previous years, the following selection criteria was used in the development of the peer group:

Companies included in the 2017 Compensation Peer Group were companies that had one or more business aspects that corresponded with one or more of the main aspects of our three business units: M&M, Rail, and Industrial. The following companies comprise the 2017 Compensation Peer Group:

45

In addition, the following companies, which were part of the 2016 Compensation Peer Group, were used as additional reference in evaluating competitive pay positioning:

For the 2017 Compensation Peer Group, median revenues for 2017 (2016 data was utilized to determine 2017 NEO compensation) were approximately $1.4 billion (as compared to the Company’s 2017 revenues of approximately $1.6 billion) and median market capitalization as of September 30, 2017 was approximately $1.5 billion (as compared to the Company’s 2017 market capitalization of approximately $1.5 billion). The following charts illustrate Harsco’s position in comparison to the 2017 Compensation Peer Group’s median by total revenues and market capitalization measured as of September 30, 2017.

Initial Benchmarking

In reviewing base salaries, target total cash compensation, and target total compensation for 2017, the MD&C Committee initially targeted each NEO’s compensation opportunity at the 50^th percentile of the combined peer group data and survey data. The MD&C Committee believes NEOs should not be compensated at either the high or low end of compensation as compared to the market, but rather should receive a reasonable level of compensation based on both the Company’s overall performance and their individual performance. The MD&C Committee then sets final compensation amounts either above or below the initial benchmarks, specifically taking into account:

46

While past performance is considered by the MD&C Committee in setting current year target compensation opportunities, the effect of current performance is much more significant in determining the level at which those compensation opportunities are earned and paid out. Our program provides each NEO an opportunity to earn a competitive level of compensation each year if we achieve our pre-established objectives, with an opportunity to earn greater amounts by helping us exceed those targets or lesser amounts when performance falls short of targets.

Impact of NEO Individual Performance on 2017 Compensation

Consistent with our performance-oriented pay philosophy, the compensation structure for the President & CEO is designed to deliver approximately 20% of the annual compensation opportunity in the form of fixed pay (base salary) and the remaining 80% in the form of variable compensation (target annual incentive compensation and target long-term equity-based compensation). The actual amount of compensation realized by the CEO may vary from this target based upon performance evaluated under the terms of our variable compensation plans. Once per year, the MD&C Committee completes an evaluation with respect to the Company’s goals and objectives and makes a report to the Board. Based upon this assessment, the CEO’s compensation was set for the 2017 fiscal year, including base salary, annual incentive target, long-term equity-based compensation, perquisites, and other benefits. When evaluating the total level of CEO compensation for the 2017 fiscal year, the MD&C Committee considered the following information:

With respect to setting the compensation for the other NEOs, the MD&C Committee strives to deliver a competitive level of total compensation to each of the NEOs by evaluating and balancing the following objectives:

Consistent with our pay for performance philosophy, target total direct compensation for our NEOs other than the President & CEO is designed to deliver approximately 65% variable compensation at target performance and 35% fixed compensation. The amounts of compensation actually realized by our NEOs will vary from the target awards based upon performance evaluated under the terms of our compensation plans.

47

Each year, the President & CEO presents his Organizational Leadership Review to the MD&C Committee to discuss the individual performance and potential of the other NEOs. Following this review, the President & CEO submits compensation recommendations to the MD&C Committee for each NEO. These recommendations address all elements of compensation, including base salary, target annual incentive compensation, long-term equity-based compensation, perquisites, and other benefits. In evaluating these compensation recommendations, the MD&C Committee considers information such as the NEOs’ individual performance, the performance of the Company, and the compensation of similarly situated executive officers as determined by the referenced benchmark data. The MD&C Committee takes into account all of the same considerations when making its compensation decisions for the President & CEO.

Elements of 2017 NEO Compensation Program

The key elements of our 2017 NEO compensation program are described in the following table:

48

Target Compensation Mix

As reflected in the following charts, the MD&C Committee approved a significant amount of each NEO’s target total compensation opportunity in the form of variable, rather than fixed, compensation.

The charts above include annual base salary, target AIP and target LTIP as of December 31, 2017. The 2017 Target Compensation Mix Average of Other NEOs chart includes data for those NEOs, excluding the President & CEO, serving as named executive officers as of December 31, 2017.

Base Salary

Base salary represents annual fixed compensation and is a standard element of compensation necessary to attract and retain talent. It is the minimum payment for a satisfactory level of individual performance for as long as the executive remains employed with the Company. Base salary is set at the MD&C Committee’s discretion after taking into account the competitive landscape including the compensation practices of the companies in our selected Compensation Peer Group and survey data from a broader index of comparable companies, our business strategy, our short- and long-term performance goals, and individual factors, such as position, salary history, individual performance and contribution, an individual’s length of service with the Company, and placement within the general base salary range offered to our NEOs.

The annual base salary rates are effective on May 1^st of the applicable fiscal year. The table below reflects the year-over-year changes in base salary approved by the MD&C Committee and effective as of December 31, 2017:

49

2017 AIP Awards

NEOs were eligible to participate in the 2017 AIP program, which provides the opportunity to earn a performance-based cash incentive based on the achievement of near-term financial results and strategic goals. All NEOs were evaluated, in significant part, based on overall Company performance to improve financial results and drive stockholder value. In its decision-making authority, the MD&C Committee reviewed the targets as established based on the 2017 Annual Operating Plan set at the beginning of the year versus actual financial results. The MD&C Committee is given discretion to reduce (but not increase) the final payout amounts for the NEOs.

Prior to 2018, Harsco’s performance-based incentives were intended to comply with the historical structure of IRC section 162(m) for the purposes of qualifying as performance-based compensation for tax deductibility purposes. To this end, incentives were awarded under the shareholder approved 2013 Equity & Incentive Plan, which identifies eligible employees covered by the plan, metrics used to assess company performance for determining incentive payments, and individual compensation limits.

Setting 2017 AIP Award Opportunities

Target annual incentive opportunities are expressed as a percentage of base salary and payouts can range from 0% to 200% of target award amounts based on performance. Targets were established by the MD&C Committee based on each NEO’s level of responsibilities and his or her ability to impact our overall results, as well as consideration of the benchmarking data as previously discussed. For 2017, there were no changes to target annual incentive levels for NEOs.

50

AIP Performance Metrics and Payouts

For 2017, all AIP payouts for NEOs were entirely dependent upon achievement of BUC performance. Performance metrics, weights and goals were developed based upon our annual operating plans, as approved by the Board, to drive alignment with commitments made to our stockholders. Specific weightings between Harsco Consolidated BUC and Business Unit BUC for each NEO is presented in the table below:

In developing the Consolidated Harsco BUC goal, we established the threshold, target and maximum levels by starting with the first component – our operating income target as approved by the Board of Directors in our annual operating plan. We then apply the second component – a fixed cost of capital rate applied to planned controllable net assets deployed. The operating income metric at threshold, target and maximum is then reduced by the fixed cost of capital (which is applied consistently across all performance levels) to derive the final BUC result at each performance level. Harsco Consolidated operating income and BUC goals are a product of the goals across the individual lines of business less a charge for Corporate operating expenses.

51

The 2017 BUC goals at the Harsco Consolidated level are presented in the table below:

The BUC goals are designed to enable business unit leadership to execute controllable strategic actions that deliver improved income generation with an efficient use of capital resources. The Harsco Consolidated BUC target which is based on two distinct and separate components: (1) an operating income target of $106.1 million minus (2) a fixed cost of capital rate applied to planned controllable net assets deployed. As our fixed capital charge exceeded the operating income target, thus Harsco’s Consolidated BUC target was negative $10.8 million. This operating income target reflects an increase of 9.5% over the 2016 operating income target. In determining the operating income target for 2017, we reviewed the prior year’s operating results and the impact of current year’s strategic objectives. An increase in Corporate spending was anticipated to support these objectives. We also anticipated modest improvements in many of Harsco’s key end-markets and the impact of a stronger U.S. dollar against various currencies. Below are specific factors by business unit which were considered impactful and contributed to the increase in the 2017 operating income target when compared with 2016 actual results.

52

The Committee established a performance range around the operating income target of 64% to 140% of target from threshold to maximum after considering the volatility that commodity and served end market uncertainty was creating within our customer base, and the results of a market review of performance ranges in the industry.

Actual Harsco Consolidated BUC achieved was $28.3 million, driven by better than planned operational performance, strong cash flows, and capital management. Stronger operating income performance resulted from the successful execution of business and cost control initiatives, favorable end market trends in the energy sector, higher commodity prices, and lower overhead costs. Better capital charge performance occurred due to more disciplined capital spending and working capital management. The MD&C Committee gave careful consideration and assessment of the management team’s achievement against the established goals. As contemplated when setting the targets, certain adjustments were made due to the impact on annual results of certain nonrecurring, unusual items. The adjustment totaled $2.1 million for a portion of bad debt expense for a customer site in Metals and Minerals that had entered into voluntary administration; the proceedings of which indicated most of the pre-administration receivables would not be paid by the customer. This adjustment was determined by the MD&C Committee to be excluded from the calculation of BUC since it did not directly reflect company or management performance and is unusual and infrequent in nature. The adjusted BUC performance produced a 188% AIP payout for Mr. Grasberger, Mr. Minan, Mr. Hochman and Ms. McKenzie, who were awarded $1,740,550, $704,851, $455,036 and $448,803 respectively.

At the business unit level, Mr. Gerson’s incentive awards are determined using an equal weighting between Harsco Consolidated BUC and Harsco Industrial BUC. Mr. Gerson’s annual goals are a balance between critical contributions to overall Harsco performance with the specific strategic initiatives of the Industrial business unit. For 2017, BUC performance for Harsco Industrial was $26 million, resulting in a payout factor of 167% for Mr. Gerson on the business unit component, and when including the Harsco Consolidated performance result, Mr. Gerson’s combined payout factor was 177.5% and he was awarded $448,183.

The 2017 AIP calculations and results were as follow for the NEOs:

Long-Term Incentive Awards

The MD&C Committee’s philosophy, where long-term compensation is balanced between performance-based and service-based pay, helps us achieve alignment of stockholder and executive interests by:

53

Setting 2017 Long-Term Award Opportunities

Target long-term incentive opportunities are expressed as a percentage of base salary and the realized value is dependent on stock price and total shareholder return over a specified period of time. Targets were established by the MD&C Committee based on each NEO’s level of responsibilities and his or her ability to impact our overall results, as well as consideration of the benchmarking data previously discussed. For 2017, there were no changes to target long-term incentive levels for NEOs from 2016 levels.

As has been our practice historically, for the LTIP award cycle granted in 2017, the MD&C Committee and the Board established the grant level for each NEO as a percentage of that NEO’s base salary. The MD&C Committee and the Board set target values for the 2017 LTIP awards with the intent that each NEO’s total direct compensation opportunity falls within a reasonable range of the market median for the NEO’s position. See the “Grants of Plan-Based Awards in Fiscal 2017” table for more information. In 2017, as discussed in the proxy statement last year, the timing of the annual LTIP Grant was changed from early May to early March to align with the timing utilized by our peers and to be consistent with our annual incentive process.

LTIP Components

Over the last several years, our LTIP program has evolved with our changing business model, feedback from our stockholders and market trends to achieve the appropriate balance of risk, retention and performance. Beginning in 2014, we included PSUs as a component of the LTIP for our Executive Leadership Team and reduced the proportion of SARs so that PSUs, SARs, and RSUs are all equally weighted. We have maintained this mix since 2015 for all NEOs.

NEO LTI Mix

54

Vesting of 2015 to 2017 Performance Share Unit Plan

The Company granted performance share units in 2015 with vesting conditioned on Harsco’s TSR performance relative to the S&P 400 MidCap index for the three-year period from 2015 through 2017. Harsco’s TSR result for the period equaled the 24^th percentile of the index, resulting in a payout at 0% of the units granted in 2015.

55

Decisions Regarding 2018 Individual Incentive Targets

At its February 2018 meeting, the MD&C Committee made the following changes to certain of our NEO’s long term incentive targets. The MD&C Committee made these changes in consideration of the executive’s compensation as compared to peer companies, additional responsibilities assumed by the executive, tenure and individual performance.

In addition, the CEO’s LTI mix was adjusted to 40% PSUs, 30% RSUs and 30% SARs while all other NEOs maintained an equal mix across all three vehicles. No adjustments were made to the 2018 annual incentive targets.

Other Compensation Elements

During 2017, we provided our NEOs with the following broad-based employee benefits on the same terms that apply to our non-executive U.S. employees:

Since defined benefit plan accruals for Harsco’s U.S. executives were frozen effective December 31, 2008, we continue to note the change in pension value representing the net effect of interest adjustments (in other words, change in present value due to shortening of the discount period) and changes in assumptions used to estimate present values. Our NEOs are also eligible to participate in the Non-Qualified Retirement Savings and Investment Plan (“NQ RSIP”), which supplements the RSIP with respect to contributions that could not be made because of Internal Revenue Service compensation and contribution limitations.

We provided other benefits to certain NEOs during 2017. While rarely used, the Board maintains a policy regarding our President & CEO’s personal use of our corporate aircraft. In the event of personal use of the corporate aircraft, our President & CEO is taxed on the imputed income attributable to personal use of our aircraft, and our President & CEO does not receive a tax gross-up from us with respect to such imputed amounts.

We offer perquisites and other personal benefits to our NEOs at competitive levels with those provided by our peer group companies, as well as the larger group of companies within the general industry that are similar in overall size and relative performance. We believe the other benefits we provided to our NEOs were necessary to help us attract and retain our senior executive team and the values of these benefits were reasonable, competitive, and consistent with the overall executive compensation program.

For more information on the perquisites and certain other benefits provided to the NEOs in 2017, see the All Other Compensation Table that serves as a supplement to the 2017 Summary Compensation Table.

56

Employment Arrangements with NEOs

The Company is not a party to any employment agreements with its NEOs. Additionally, no offer letter arrangements were outstanding between our NEOs and the Company in 2017.

Potential Payments upon Change in Control and Other Potential Post-Employment Payments

Change in Control Severance Agreements

We are currently a party to change in control severance agreements with Messrs. Grasberger, Minan, Hochman, Gerson and Ms. McKenzie. These change in control severance agreements reflect what we believe to be a market-based approach to a potential change in control scenario and incorporated several stockholder-favored compensation practices, including:

Mr. Grasberger is entitled to receive double-trigger severance benefits equal to three times his highest base salary in effect during the period beginning 90 days prior to the change in control through the date of termination, plus three times his highest target annual incentive for the year of termination. Each of Messrs. Minan, Hochman, Gerson and Ms. McKenzie is entitled to receive double-trigger severance benefits equal to two times his or her highest base salary in effect during the period beginning 90 days prior to the change in control through the date of termination, plus two times his or her highest target annual incentive for the year of termination. Each change in control severance agreement provides for a rolling three-year term that renews each year, subject to certain exceptions.

The change in control severance agreements are reviewed on a regular basis, though not necessarily as part of the annual compensation review. The MD&C Committee believes the change in control severance agreements serve the following purposes:

Other Potential Post Employment Payments

Upon certain types of terminations of employment not related to a change in control, payments under various Company policies and plans may be paid to NEOs. These events and amounts are more fully explained under the heading “Termination or Change in Control Arrangements.”

57

Stock Ownership Guidelines

In 2017, we continued to maintain stock ownership guidelines that applied to the NEOs. Our stock ownership guidelines encourage the retention of stock acquired through our LTIP awards. No shares may be sold by participants until their applicable ownership guidelines are satisfied, subject to a hardship exception administered by the MD&C Committee.

The stock ownership guidelines are established as a multiple of each NEO’s base salary and were benchmarked against the stock ownership guidelines for similarly situated executives at peer group companies. They were also based on the Board’s determination of appropriate share ownership levels based on our compensation system. Under the guidelines, each NEO is encouraged to own a specific amount of our common stock and is restricted from selling shares until the guideline has been satisfied. The share ownership levels (based on fair market value as measured periodically) for each NEO for 2017 were as follows:

Our NEOs have five years from the date they are first granted LTIP awards to comply with the guidelines. If a NEO is promoted into a position with greater ownership requirements, that individual has five additional years to comply with the new guideline. All common stock held by the NEOs, whether acquired as a result of an LTIP award or otherwise, is included in determining whether they have achieved the applicable ownership guideline. Unvested stock options and unvested SARs are not included in calculating whether the guidelines have been met. Failure to meet the guidelines within the applicable five-year period will result in a review by the MD&C Committee to determine the cause of such failure and to develop an appropriate corrective action plan.

At December 31, 2017, all NEOs have met their ownership guidelines.

Right to Recover Incentive Compensation

Consistent with the Wall Street Reform and Consumer Protection Act (the “Dodd-Frank Act”), the Company and the Board reserve the right to recover (or “clawback”) from certain current and/or former key employees any wrongfully earned performance-based compensation, including stock-based awards, under the following circumstances:

These provisions are designed to deter and prevent detrimental behavior and to protect our investors from financial misconduct.

58

Policies on Hedging and Pledging of Shares

Consistent with the Dodd-Frank Act, the Company’s Insider Trading Policy prohibits all Board members, employees, including corporate officers, from engaging in any transaction in which they may profit from short-term speculative swings in the value of the Company securities (or “hedging”). For this purpose, “hedging” includes “short-sales” (selling borrowed securities which the seller hopes can be purchased at a lower price in the future) or “short sales against the box” (selling owned, but not delivered securities), “put” and “call” options (publicly available rights to sell or buy securities within a certain period of time at a specified price or the like), and other hedging transactions designed to minimize the risk inherent in owning Common Stock, such as zero-cost collars and forward sales contracts.

Additionally, Board members and executives are prohibited from pledging shares as collateral for a loan or in a margin account.

Policy Regarding Tax and Accounting Impact on Executive Compensation

Section 162(m) of the Internal Revenue Code generally limits to $1 million the U.S. federal tax deductibility of compensation paid in one taxable year by publicly-traded corporations to certain executive officers (and, beginning in 2018, to certain former executive officers). Historically, qualified “performance-based compensation” as was defined under Section 162(m) was not subject to the limits on deductibility, provided such compensation meets certain requirements, including stockholder approval of the material terms of the compensation. However, this exception has now been repealed, effective for taxable years beginning after December 31, 2017, unless certain transition relief for certain compensation arrangements in place as of November 2, 2017 is available.

In certain cases, we have sought to preserve this deductibility of compensation paid to our NEOs while maintaining a compensation program that effectively attracts and retains high performing executives in a highly competitive environment. However, on occasion we may not have been able to (or we may not be able to) satisfy all conditions of the Internal Revenue Code for deductibility and still meet our compensation needs. As a result, we may from time to time choose to pay compensation that would otherwise not be deductible under Section 162(m) if we believe that it is appropriate and in our and our stockholders’ best interests. Furthermore, even if the MD&C Committee has intended (or should desire in the future) to grant compensation that qualifies for the performance-based exception, we cannot guarantee that such compensation will so qualify or ultimately will be deductible.

Compensation Committee Report

The MD&C Committee has reviewed and discussed the Compensation Discussion & Analysis set forth above with management. Based on this review and discussion, the MD&C Committee recommended to the Board that the Compensation Discussion & Analysis be included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2017 and our Proxy Statement for our 2018 Annual Meeting of Stockholders, for filing with the SEC.

SUBMITTED BY THE MANAGEMENT DEVELOPMENT AND COMPENSATION COMMITTEE OF THE BOARD OF DIRECTORS:

J. F. Earl, Chairman

S. E. Graham

T. D. Growcock

P. C. Widman

M. Longhi

The foregoing report shall not be deemed to be “soliciting material” or to be “filed” with the SEC or subject to Regulation 14A promulgated by the SEC or Section 18 of the Exchange Act.

59

Compensation Policies and Practices as They Relate to Risk Management

In 2017, Pay Governance, along with senior management, reviewed our compensation policies and practices for all employees. They concluded, and the MD&C Committee concurred, that any risks arising from our compensation policies and practices are not reasonably likely to have a material adverse impact on the Company. In addition, we reviewed the relationship between our risk management policies and practices and the incentive compensation we provide to our NEOs and other key employees to confirm that our incentive compensation does not encourage unnecessary and excessive risk taking.

The findings of these reviews indicated that:

Furthermore, as described above, compensation decisions may include the subjective use of negative discretion, which has the ability to restrain the influence of formulae or objective factors on excessive risk taking.

60

2017 Summary Compensation Table

The following table presents the compensation provided to our NEOs for services rendered to us in 2015, 2016 and 2017, as applicable: