# LANXESS Corporation — Hazardous Materials Safety Interpretation **Citation:** 20-0084 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 2021-05-06 20-0084 response to LANXESS Corporation concerning 173.124, 173.125. ## Document text <<>> U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration 1200 New Jersey Avenue, SE Washington, DC 20590 May 6, 2021 Cyndi Fink Distribution Safety Manager LANXESS Corporation 111 RIDC Park West Drive Pittsburgh, PA 15275 Reference No. 20-0084 Dear Ms. Fink: This letter is in response to your October 29, 2020, letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to classifying organic acid chlorides. Specifically, you seek clarification of the classification criteria for dangerous when wet (Division 4.3) materials as specified in §§ 173.124(c) and 173.125(d) of the HMR. In your letter, you state that your company contracted with a laboratory to conduct testing in accordance with the United Nations (UN) Test N.5 of the UN Manual of Tests and Criteria and § 173.124(c) of the HMR to determine whether some organic acid chlorides should be classed as a Division 4.3 material. You state that while the UN Test for Division 4.3 materials requires testing for the emission of flammable gases, § 173.124(c) of the HMR indicates that both flammable or toxic gases must be considered for classifying a substance as a Division 4.3 material. Additionally, in your letter you state that samples of your material did not emit any flammable gases during testing; however, they did emit hydrogen chloride, a toxic gas. You ask for PHMSA to clarify its position for requiring a material to be classed as a Division 4.3 if it emits a toxic gas during testing, or if this requirement should be harmonized with international test methods and only be considered a Division 4.3 material if flammable gasses are emitted during testing. PHMSA acknowledges that there is a difference between the international regulations and the HMR pertaining to the criteria for the classification of a Division 4.3 material. The international regulations do not mention the emission of toxic gases as criteria in assigning a material to Division 4.3, while the emission of toxic or flammable gas would be the criteria to assign a material to Division 4.3 in accordance with the HMR. It is the opinion of this Office that water- reactive materials that produce toxic gases still present a hazard that should be addressed in the <<>> HMR, and that until this issue is addressed, you may use the same criteria for Packing Group (PG) assignment currently specified in § 173.125(d) for measuring the emission of flammable gasses as for measuring the emission of toxic gasses. I hope this information is helpful. Please contact us if we can be of further assistance. Sincerely, T. Glenn Foster Chief, Regulatory Review and Reinvention Branch Standards and Rulemaking Division <<>> Larson From: 20-0084 Subject: To: INFOCNTR (PHMSA) Dodd, Alice (PHMSA); Hazmat Interps Date: FW: Request for letter of interpretation Attachments: 2020-10-27 Class 4.3 Toxic Gas LOI request.pdf Friday, October 30, 2020 12:49:52 PM Hi Alice, Please see attached for a letter of interpretation request. Please contact our office with any questions. Thank you, Sarah (HMIC) From: cyndi.fink@lanxess.com [mailto:cyndi.fink@lanxess.com] Sent: Thursday, October 29, 2020 12:10 PM To: INFOCNTR (PHMSA) < INFOCNTR.INFOCNTR@dot.gov> Cc: Ernest Marcel ; sebastian.buchner@lanxess.com Subject: Request for letter of interpretation CAUTION: This email originated from outside of the Department of Transportation (DOT). Do not click on links or open attachments unless you recognize the sender and know the content is safe. Please see attached request for a letter of interpretation regarding 49CFR173.124(c). Thank you. *uit4+t444++444++44444444++4+4444444+4444444444444444444444.4kk Cyndi Fink, CDGP, DGSA Distribution Safety Manager Product Safety & Regulatory Affairs LANXESS Corporation 111 RIDC Park West Drive | Pittsburgh, PA 15275-1112 Cell: 412-337-2350 | Office: 412-809-4774 | cyndi.fink@lanxess.com ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `c0ec0fac22a01e2e685a254bbf6f81580d87198313aa86f006d16c3d5700ae15` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-23T00:02:02.351Z - Document slug: `phmsa-interpretation-20-0084` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [ "LANXESS Corporation" ], "individuals": [ "Cyndi Fink" ], "refIds": [ "20-0084" ], "catalogDates": [ "2021-05-06" ], "catalogParts": [ 173 ], "catalogRowCount": 2, "sourceRecordUrls": [ "https://www.phmsa.dot.gov/node/72656" ], "linkedAttachmentUrls": [], "unavailableResponseUrls": [], "duplicateRepresentationUrls": [], "citedSections": [ "173.124", "173.124(c)", "173.125", "173.125(d)" ], "catalogPageUrls": [ "https://www.phmsa.dot.gov/regulations/title49/section/173124", "https://www.phmsa.dot.gov/regulations/title49/section/173125" ], "pdfUrls": [ "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/standards-rulemaking/hazmat/interpretations/75021/200084.pdf" ], "representations": [ { "viewUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/standards-rulemaking/hazmat/interpretations/75021/200084.pdf", "detailUrl": null, "detailHtmlPath": null, "pdfUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/standards-rulemaking/hazmat/interpretations/75021/200084.pdf", "pdfArtifactPath": "data/sources/phmsa-interpretations/20-0084-4eba1ddd23.pdf", "pdfArtifactSha256": "acfe8aa5f3a9e49fd5ea3f83b26aefe2f7f9a787af41fe40f34729afca45950c", "extractedTextPath": "data/sources/phmsa-interpretations/20-0084-4eba1ddd23.v2.txt", "extractedTextSha256": "f7d7354ab68a1610519125f273b3a7039bd54134435f4dbdce848d280b7fc1c2", "pageCount": 3, "extractionVersion": 2 } ], "caveat": "Interpretations apply regulations to the facts presented and do not create independently enforceable requirements.", "jurisdiction": "US" } ```