Leading Independent Proxy Advisory Firms ISS and Glass Lewis Recommend Heritage-Crystal Clean Shareholders Vote “FOR” the All-Cash Transaction with J.F. Lehman & Company - Seite 2

About J.F. Lehman & Company

J.F. Lehman & Company is a leading private equity investment firm focused on the aerospace, defense, maritime and environmental sectors. This investment strategy reflects the firm’s deep experience in and commitment to these sectors since the firm’s founding three decades ago. Headquartered in New York, NY, the firm currently has approximately $4.5 billion of assets under management. To learn more, please visit www.jflpartners.com.

Additional Information and Where to Find It

This communication may be deemed to be solicitation material in respect of the transaction contemplated by the merger agreement (the “proposed merger”). In connection with the proposed merger, Crystal Clean filed with the U.S. Securities and Exchange Commission (the “SEC”) a definitive proxy statement (the “Proxy Statement”) on Schedule 14A on August 31, 2023. Crystal Clean has mailed the Proxy Statement and a proxy card to each stockholder entitled to vote at the special meeting relating to the proposed merger. This communication is not a substitute for the Proxy Statement or any other document that Crystal Clean may file with the SEC or send to its stockholders in connection with the proposed merger. BEFORE MAKING ANY VOTING DECISION, INVESTORS AND STOCKHOLDERS OF CRYSTAL CLEAN ARE URGED TO READ ALL RELEVANT DOCUMENTS FILED WITH THE SEC, INCLUDING THE PROXY STATEMENT, BECAUSE THEY CONTAIN OR WILL CONTAIN IMPORTANT INFORMATION ABOUT THE PROPOSED MERGER. Investors and security holders are or will be able to obtain the documents (if and when available) free of charge at the SEC’s website at www.sec.gov, or free of charge from Crystal Clean by directing a request to Mark DeVita, EVP & CFO, at [e-mail].

Participants in the Solicitation

Crystal Clean and JFLCO and their respective directors, executive officers and other members of management and employees, under SEC rules, may be deemed to be “participants” in the solicitation of proxies from stockholders of Crystal Clean in favor of the proposed merger. Information about Crystal Clean’s directors and executive officers is set forth in the Proxy Statement. Additional information concerning the interests of Crystal Clean’s participants in the solicitation, which may, in some cases, be different than those of Crystal Clean ’s stockholders generally, is also set forth in the Proxy Statement.