# Department of California Highway Patrol — Hazardous Materials Safety Interpretation **Citation:** 03-0146 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 2003-07-18 03-0146 response to Department of California Highway Patrol concerning 177.848. ## Document text <<>> .S. Departmer Research and f Transportatior 400 Seventh St., S.W. Washington, D.C. 20590 Special Programs Administratior JUL 18 2003 Officer George Barber, CHPO, 10665 Ref. No.: 03-0146 Department of California Highway Patrol California Highway Patrol, Valley Division 11337 Trade Center Drive Rancho, Cordova, CA Dear Officer Barber: This responds to your June 6, 2003 letter regarding the segregation requirements under the Hazardous Materials Regulations (HIMR; 49 CFR Parts 171-180), as they apply to various chemicals transported in the same vehicle. You enclosed copies of several photographs of boxes on pallets inside the vehicle. While performing an inspection on a vehicle transporting hazardous materials classed as Division 6.1 (poison), PG I, Poison Inhalation Hazard, Zone B; Class 3 (flammable liquid); Class 8 (corrosive); Division 4.1 (flammable solid); Division 4.3 (dangerous when wet); and Division 5.1 (oxidizers), you discovered that the van was refrigerated and had a metal ribbed floor. The ribs are approximately 1- inch wide and 1-inch deep. The ribbed floor allows cold air to circulate around the product to maintain a constant temperature, and also allows melting ice to drain to the back of the van and out through the rear doors. You asked if hazardous materials in boxes on wooden pallets placed on a "ribbed floor" would be considered proper separation, sufficient to prevent commingling of liquid chemicals. Hazardous materials may not be loaded, transported, or stored together, except as specified in the "Segregation Table" in §177.848(d). The provisions for separation can be met by placing barriers (i.e., impediments, obstructions, dividers, packages of non-hazardous materials, or intervening space) between packages inside of the transport vehicle or freight container that prevent commingling of materials in the event of leakage from the packages. Regardless of the methods of separation used, Class 8 (corrosive) liquids may not be loaded above or adjacent to Class 4 (flammable solid) or Class 5 (oxidizing) materials; except that shippers may load truckload shipments of such materials together when it is known that the mixture would not cause a fire or a dangerous evolution of heat or gas (see §177.848(e)(3)). The hazardous materials mentioned above are not prohibited from being transported in the same vehicle. Boxes shrink-wrapped on pallets, separated by intervening space or packages containing non- hazardous materials, satisfy the requirement for "separation." Whether the boxes on wooden pallets are 177,848 030146 <<>> on a "ribbed floor" is not relevant in determining that the requirement for "separation" is being met. A material poisonous by inhalation leaking from a package can emit toxins that permeate or spread throughout areas of a van or transport vehicle, and can be immediately harmful to any persons entering the van or vehicle. I hope this satisfies your inquiry. If we can be of further assistance, please contact us. Sincerely, Shoa Doy Susan Gorsky k Office of Hazardous Materials Standards Senior Transportation Regulations Specialist <<>> State of California Business, Transportation and Housing Agency DEPARTMENT OF CALIFORNIA HIGHWAY PATROL GRAY DAVIS, Governor 11337 Trade Center Drive California Highway Patrol, Valley Division (916) 464-2556 EXT 13 Rancho Cordova, CA (800) 735-2922 (Voice) (800) 735-2929 (TT/TDD) Engrum June 6, 2003 5177-848 File No.: 010665 segregation 83-0146 To: U.S. Department of Transportation Research and Special Programs Administration Washington, DC 20590 400 Seventh Street S.W. From: Officer George Barber 10665 - transported in the same vehicle. Please provide a letter of interpretation on the following issues relating to incompatible chemicals While performing a vehicle inspection on a vehicle transporting hazardous materials classed as division 6.1, PGI, Poison Inhalation Hazard Zone B, Class 3, Class 8 liquid, Division 4.1, Division 4.3, and Division 5.1. I discovered that the vehicle in use was a refrigerated van with a metal ribbed floor. The ribs were approximately one inch wide and one inch deep. The purpose of the ribs is two fold. First, the ribs allow the cold air to circulate around the product in transit to maintain a constant temperature. Second, the ribs allow melting ice to drain to the back of the van and out through the rear doors. My questions are as follows: (1) In reading previous letters of interpretation, I understand that segregation must be complished by a non-permeable barrier, absorbent material, or non-reactive freigh onsidering the nature of the floor, would a barrier of wood pallets on the top of the ribs b (2) Considering the nature of a material poisonous by inhalation, if the material were to leak could sufficient to prevent commingling of liquid chemicals? the toxins permeate the open area of the van and react with other chemicals that may leak? POWER EATER· ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `a55bc7558c06f48f18d6b69cae151a74eda05cb4d9c21a72d9bee15b88afa376` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-25T17:14:40.853Z - Document slug: `phmsa-interpretation-03-0146` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [ "Department of California Highway Patrol" ], "individuals": [ "Officer George Barber, CHPO, 10665" ], "refIds": [ "03-0146" ], "catalogDates": [ "2003-07-18" ], "catalogParts": [ 177 ], "catalogRowCount": 1, "sourceRecordUrls": [ "https://www.phmsa.dot.gov/node/68826" ], "linkedAttachmentUrls": [], "unavailableResponseUrls": [], "duplicateRepresentationUrls": [], "citedSections": [ "177.848", "177.848(d)" ], "catalogPageUrls": [ "https://www.phmsa.dot.gov/regulations/title49/section/177848" ], "pdfUrls": [ "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2003/030146.pdf" ], "representations": [ { "viewUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2003/030146.pdf", "detailUrl": null, "detailHtmlPath": null, "pdfUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2003/030146.pdf", "pdfArtifactPath": "data/sources/phmsa-interpretations/03-0146-a73de5ce71.pdf", "pdfArtifactSha256": "a1730357e33bd4edda9f4c0f09855094c1d3bb3dcbc5b7d7f7a373a7af3c325d", "extractedTextPath": "data/sources/phmsa-interpretations/03-0146-a73de5ce71.v2.txt", "extractedTextSha256": "be7f8d080d878513cd1f4d1fc11293e6a349b3ff4d69bfef1e19b2fb6c91b414", "pageCount": 3, "extractionVersion": 2 } ], "caveat": "Interpretations apply regulations to the facts presented and do not create independently enforceable requirements.", "jurisdiction": "US" } ```