# Clean Earth — Hazardous Materials Safety Interpretation **Citation:** 22-0106 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 2022-12-12 22-0106 response to Clean Earth concerning 172.502. ## Document text <<>> 1200 New Jersey Avenue, SE Washington, DC 20590 U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration December 12, 2022 Nicholas Prevosti Environmental Health and Safety Manager Clean Earth 115 Jacobus Avenue Kearny, NJ 07032 Reference No. 22-0106 Dear Mr. Prevosti: This letter is in response to your October 6, 2022, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to prohibited display of placards. Specifically, you ask whether a flip placard displaying “blank” white panels constitutes prohibited placarding in accordance with § 172.502(a)(2). When turned to the “blank” side, a flip placard maintains the square-on-point design (i.e., shape of a placard) but does not display any hazard communication information. The answer is no, display of a “blank” white flip placard does not constitute prohibited placarding. Similarly, an empty placard holder frame also does not constitute prohibited placarding. I hope this information is helpful. Please contact us if we can be of further assistance. Sincerely, Dirk Der Kinderen Chief, Standards Development Branch Standards and Rulemaking Division <<>> 22-0106 Patrick From: INFOCNTR (PHMSA) To: Hazmat Interps Subject: FW: Clarification on blank Square on Point fillers and interpretation letter 12-0139 Date: Monday, October 17, 2022 4:11:16 PM Attachments: 120139 misleading information placard holders.pdf Please see below request for letter of interpretation. An older letter of interpretation was attached as well but it is a different scenario. Thanks, Jonathon, HMIC From: Prevosti, Nicholas Sent: Thursday, October 6, 2022 1:37 PM To: INFOCNTR (PHMSA) Cc: Barone, Joe ; Fixter, Robert P ; Koziol, David ; Radichel, Jakob ; White, Leigha Subject: Clarification on blank Square on Point fillers and interpretation letter 12-0139 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. To Whom It May Concern, Please clarify if the attached interpretation letter intends to mean that the shape (square on point) on its own, blank, white, with no markings would be considered to be confused with prescribed placards. It is clear that a square on point in conjunction with a red N would meet the prohibition of 172.502(a)(2). The reason for this request for clarification is that it is common practice to flip placards to the blank white square on point side in “slide in holders” and “flip” placards on gondola rail cars and over the road trucks. As they are blank, and white, there are no markings that could be confused with any other placard’s color, design, shape or content. It would seem that the reference to “shape” in the regulation would have to refer to the shape of a marking on a placard and not the shape of a placard itself, as the shape of a square on point is a ubiquitous shape and would have far ranging prohibitions. For example, the permanently affixed “flip” placards cannot be removed from the conveyance, so a blank, white square on point must be used as a “null filler” to show there is no placard. Even an empty slide in holder is the shape and size of a square on point, regardless of the presents of a blank, white null filler. Thank you for your assistance in this matter. § 172.502 Prohibited and permissive placarding. (a) Prohibited placarding. Except as provided in paragraph (b) of this section, no person may affix or display on a packaging, freight container, unit load device, motor vehicle or rail car - (1) Any placard described in this subpart unless - <<>> (i) The material being offered or transported is a hazardous material; (ii) The placard represents a hazard of the hazardous material being offered or transported; and (iii) Any placarding conforms to the requirements of this subpart. (2) Any sign, advertisement, slogan (such as “Drive Safely”), or device that, by its color, design, shape or content, could be confused with any placard prescribed in this subpart. Nicholas Prevosti CHMM Environmental Health and Safety Manager M 201-273-4796 nprevosti@harsco.com www.cleanearthinc.com O 973-344-4004 x 1791 115 Jacobus Avenue, Kearny, NJ 07032 <<>> U.S. Department ·.)f Transportation ."ipeline and Hazardous ;,1aterials Safety "'.dministration Sergeant Brad Wagner Carrier Enforcement Division Nebraska State Patrol P.O. Box 94907 Lincoln, Nebraska 68509-4907 Ref. No. 12-0139 :Jo ~J•"'N JP.rsev 1\ven11e SE 'i:.1sh1nqton. DC 20590 ,iJl 2 5 2012 Dear Sergeant Wagner: This responds to your June 19, 2012 request for clarification on prohibited placarding under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). Specifically, you asked if a red "N" on a white square on point background shown in your attached photographs constitutes a prohibited sign under§ 172.502(a)(2). Section 172.502(a)(2) provides that: [N]o person may affix or display on a packaging, freight container, unit load device, motor vehicle or rail car. .. any sign, advertisement, slogan (such as ""Drive Safely"), or device that, by its color, design, shape, or content, could be confused with any placard prescribed in this subpart. This prohibition is intended to limit the potential dilution of hazard communication provided-by the appropriate hazardous materials placards. The display in the photographs you provided is similar in "shape" (square on point configuration) to that of hazardous materials placards, and could be confused with prescribed placards in the HMR. Therefore, the red "N" on a white square on point background is prohibited under § 172.502(a)(2). I hope this answers your inquiry. If you need additional assistance, contact this office at (202) 366-8553. Sincerely, Robert Benedict Chief, Standards Development Branch Standards and Rulemaking Division <<>> Dave Heineman Governor STATE OF NEBRASKA NEBRASKA STATE PATROL Colonel David A. Sankey Superintendent P.O. Box 94907 Lincoln, Nebraska 68509-4907 Phone: (402) 471-4545 June 19,2012 13ocJffie ~ l 12... ~o~(a){?.) Pla.carc11f1j lh-'013'1 Charles E. Betts Director, Standards and Rulemaking Division U.S. DOT/PHMSA (PHH-10) 1200 New Jersey Avenue, SE East Building, 2nd Floor Washington, DC 20590 Dear Mr. Betts: Please provide a determination on whether a red "N" on a white square on point background in the attached photos constitute a prohibited sign under § 172.502(a)(2). Thank you for your time and attention in this matter. Respectfully, Brad Wagner, Sergeant Carrier Enforcement Division Enclosures: (2) Cc: Captain Krolikowski File AN INTERNATIONALLY ACCREDITED LAW ENFORCEMENT AGENCY An Equal Opportunity/Affirmative Action Employer Printed with soy ink on recycled paper ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `8bfe2e43bd8d1e8ff205ddd6a2410b11415f00a46e579ae32527b13a2abcd2b8` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-22T17:22:11.904Z - Document slug: `phmsa-interpretation-22-0106` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [ "Clean Earth" ], "individuals": [ "Nicholas Prevosti" ], "refIds": [ "22-0106" ], "catalogDates": [ "2022-12-12" ], "catalogParts": [ 172 ], "catalogRowCount": 1, "sourceRecordUrls": [ "https://www.phmsa.dot.gov/node/73441" ], "linkedAttachmentUrls": [], "unavailableResponseUrls": [], "duplicateRepresentationUrls": [], "citedSections": [ "172.502", "172.502(a)(2)" ], "catalogPageUrls": [ "https://www.phmsa.dot.gov/regulations/title49/section/172502" ], "pdfUrls": [ "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/standards-rulemaking/hazmat/interpretations/77046/220106.pdf" ], "representations": [ { "viewUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/standards-rulemaking/hazmat/interpretations/77046/220106.pdf", "detailUrl": null, "detailHtmlPath": null, "pdfUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/standards-rulemaking/hazmat/interpretations/77046/220106.pdf", "pdfArtifactPath": "data/sources/phmsa-interpretations/22-0106-9fc42c70ec.pdf", "pdfArtifactSha256": "05ad470e7c850ccc1d9f791c948fc87dbce1c86ace158768f35d9885894cb06b", "extractedTextPath": "data/sources/phmsa-interpretations/22-0106-9fc42c70ec.v2.txt", "extractedTextSha256": "be0c9ccf54b3dcccdf54241064b7d70c774e08a3fe4ba2e25f0166bcd9c9f824", "pageCount": 5, "extractionVersion": 2 } ], "caveat": "Interpretations apply regulations to the facts presented and do not create independently enforceable requirements.", "jurisdiction": "US" } ```