Ambipar应急响应-A美国股市招股说明书(2025-09-25版)

Ambipar Emergency Response This prospectus supplement updates, amends and supplements the prospectus contained in our RegistrationStatement on Form F-1 (as supplemented or amended from time to time, the “Prospectus”) (RegistrationNo.333-270493). This prospectus supplement is being filed to update, amend and supplement the information included in theProspectus with the information contained in our Report on Form 6-K, furnished to the Securities and ExchangeCommission (the “SEC”) on September 22, 2023 (the “Form 6-K”). Accordingly, we have attached the Form6-K to this prospectus supplement. This prospectus supplement is not complete without the Prospectus. This prospectus supplement should be readin conjunction with the Prospectus, which is to be delivered with this prospectus supplement, and is qualified byreferencethereto,except to the extent that the information in this prospectus supplement updates orsupersedes the information contained in the Prospectus. Please keep this prospectus supplement with yourProspectus for future reference. Our Class A ordinary shares, par value $0.0001 (“Class A Ordinary Shares”) and our warrants (“Warrants”) arelistedon the NYSE American LLC(the“NYSE American”)under the trading symbols“AMBI”and“AMBI.WS”. On September 24, 2025, the closing price of our Class A Ordinary Shares on the NYSE Americanwas $3.41 per share and the most recent closing price of our Warrants on the NYSE American was $0.07 perwarrant. Investing in our securities involves a high degree of risk. See “Risk Factors” beginning on page 21 of theProspectus for a discussion of information that should be considered in connection with an investment inour securities. Neither the U.S. Securities and Exchange Commission nor any other regulatory body has approved ordisapproved of these securities or determined if the Prospectus or this prospectus supplement is truthfulor complete. Any representation to the contrary is a criminal offense. The date of this prospectus supplement is September 24, 2025. UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWashington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUERPURSUANT TO RULE 13a-16 OR 15d-16UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of September, 2025 Commission File Number: 001-41638 AMBIPAR EMERGENCY RESPONSE(Exact name of registrant as specified in its charter) Avenida Angélica, nº 2346, 5th FloorSão Paulo, São Paulo, Brazil, 01228-200Tel: +55 (11) 3526-3526(Address of principal executive office) Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form40-F: Form 20-F☒Form 40-F☐ Ambipar Emergency Response Announces Leadership Changes São Paulo, Brazil – September24, 2025– Ambipar Emergency Response (NYSE American: AMBI) (“AmbiparResponse” or the “Company”) announces the following leadership changes: Pedro Petersen has stepped down from his position as CFO of Ambipar Response effective September 24, 2025and will transition to other roles within the Ambipar Group. Mr. Ricardo Chagas, will accumulate the role whilethe Company’s Board seeks for a replacement. About Ambipar Emergency Response Ambipar Response specializes in environmental services, and operates in six main business units: emergencyresponse, fire response, marine response, medical response, industrial response and environmental response.The Company is present in 41 countries across all six continents, providing standardized services across allregions. The Company was founded in 1995 by Tércio Borlenghi Jr. For more information, visit ambipar.com and http://ir-response.ambipar.com/ Forward-Looking Statements This press release contains “forward-looking statements” within the meaning of the “safe harbor” provisionsof the Private Securities Litigation Reform Act of 1995. These forward-looking statements are made only as ofthe date they first issued and are based on current expectations, estimates, forecasts and projections as well asthe beliefs and assumptions of management. These statements identify prospective information and may includewordssuch as“believe,”“may,”“will,”“aim,”“estimate,”“continue,”“anticipate,”“intend,”“expect,”“forecast,”“plan,”“predict,”“project,”“potential,”“aspiration,”“objectives,”“should,” “purpose,” “belief,” and similar, or variations of, or the negative of such words and expressions,although not all forward-looking statements contain these identifying words. Forward-looking statements are subject to a number of risks and uncertainties, many of which involve factors orcircumstances that are beyond Ambipar Response’s control. Ambipar Response’s actual results could differ materially from those stated or implied in forward-lookingstatements due to a number of factors, including but not limited to: more intense competition than expected,lower addition of new clients, regulatory measures, more investments in our business than expected, and ourinability to execute successfully upon our strategi