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OSHA Hazard Communication Letters of Interpretation
Hazard evaluation requirements under the Hazard Communication standard.
- Issued
- Record type
- Interpretation
- Historical standard
- 1910.1200, original 1983 rule (PDF)
- Current standard
- HCS 2024, as amended
ILPI assessment: Methylene-chloride no-label rationale superseded
This letter addresses the original 1983 Hazard Communication Standard (HCS), which is now obsolete. Do not rely on the appended March 7 letter's statement that methylene chloride needs no carcinogen labeling because it is absent from IARC/NTP lists. Current 1910.1052(k) requires HCS compliance for methylene chloride and expressly includes cancer among the hazards to address. Under the current HCS, classification follows paragraph (d) and Appendix A.6, not listing status alone.
Methylene chloride (dichloromethane) is now reasonably anticipated to be a human carcinogen in NTP's Report on Carcinogens (PDF) and IARC Group 2A, probably carcinogenic to humans. The incoming letter's 500 ppm OSHA limit is also obsolete: current 1910.1052(c) sets 25 ppm as an 8-hour TWA and 125 ppm as a 15-minute STEL.
Professional judgment remains important, but it must apply current evidence and classification criteria. Use current mixture rules and SDS ingredient-disclosure requirements, rather than treating the historical 1%/0.1% discussion or exposure below a PEL as a blanket waiver. This comparison does not determine the classification or exemption status of a particular modern ribbon formulation.
Last reviewed: .
About this ILPI assessment
This comparison with current requirements is not a finding that OSHA has formally withdrawn this letter. This assessment reflects editorial judgment informed by human review and AI assistance. It is an opinion, may contain errors or omissions, and is not an official OSHA determination. For guidance on how OSHA requirements apply to your circumstances, contact your local OSHA office.
OSHA's notice about interpretation letters
The following notice is published on OSHA's interpretation pages; it is general guidance, not a letter-specific withdrawal notice.
OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.
Source: OSHA's original letter page.
March 12, 1986
Mr. Loren Anderson, CIH
International Business Machines, Corp. [ILPI Says: This unit was spun off as Lexmark]
740 New Circle Road
Lexington, Kentucky 40511
Dear Mr. Anderson:
This letter is in reference to our previous telephone conversation on March 12 regarding hazard evaluation.
Hazard evaluation is a process which relies heavily on the professional judgment of the evaluator. Employers evaluating chemicals shall describe in writing the procedures they used to determine the hazards of the chemical they evaluate. If a determination has been made that a hazard does not exist, then the labeling and material safety data sheet requirements will not apply.
[ILPI note: Under the current HCS, professional judgment must apply the current classification criteria and available evidence; it does not provide discretion to disregard a hazard.]
Sincerely,
John B. Miles, Jr., Director
Directorate of Field Operations
March 7, 1986
Loren Anderson, CIH
International Business Machines, Corp. [ILPI Says: This unit was spun off as Lexmark]
740 New Circle Road
Lexington, Kentucky 40511
Dear Mr. Anderson:
Thank you for your letter dated January 28 in regards to the Hazard Communication Standard. Please accept my apology for the delay in response. The overwhelming number of letters and telephone calls regarding the Hazard Communication Standard has caused unavoidable delays in responding to the public's concerns.
Methylene chloride has been shown through established scientific studies to be a suspect carcinogen. However, since the chemical is not listed as a carcinogen by IARC or the NTP, labeling is not listed as a carcinogen by IARC or the NTP, labeling requirements are not necessary.
[ILPI note: This historical no-label rationale is superseded. See current methylene chloride hazard communication and current carcinogenicity criteria. The repeated words are also present in OSHA's online original.]
Material safety data sheets are required to be prepared if the chemical has been determined to be a health hazard and comprises 1% or greater of the composition, except that chemicals identified as carcinogens shall be listed if the concentrations are 0.1 % or greater.
[ILPI note: Use current mixture criteria and SDS Section 3; these historical percentages are not a universal current exemption.]
The material safety data sheet must provide a health hazard description of the chemical based on the positive studies of carcinogenicity for methylene chloride. The material safety data sheet must state the studies have indicated that it is a suspect carcinogen.
If we may be of further assistance on this matter please feel free to contact our office at (202)523-8036.
Sincerely,
John B. Miles, Jr., Director
Directorate of Field Operations
January 28, 1986
Mr. Dave Smith
Director, Office of Health
Compliance Assistance
USDOL-OSHA
200 Constitution Avenue
Washington D.C. 20210
APPLICABILITY OF 29 CFR 1910.1200 TO TYPEWRITER AND PRINTER RIBBONS CONTAINING LOW LEVELS OF METHYLENE CHLORIDE
We currently manufacture a typewriter/printer ribbon that uses methylene chloride in one of the manufacturing processes. Because of the nature of the process, a small amount of residual methylene chloride remains in the ribbon as it is shipped to customers. Currently, the level of methylene chloride in each ribbon is less than 0.1% by weight.
In order to make our manufacturing process more efficient, we are contemplating a change that would raise the residual methylene chloride to a maximum of 0.5% by weight. Extensive airborne monitoring has been performed on typewriters and printers using ribbons with 0.5% to 1% residual methylene chloride. Even under the most extraordinary operating conditions, the highest level of methylene chloride measured at or around the machine is only 0.12 PPM. This is over 4000 times below the current OSHA Permissible Exposure Limit of 500 PPM. Although there have been conflicting studies about the carcinogenicity of methylene chloride, neither IARC nor the latest NTP Annual Report list it as a carcinogen. Since the ribbon is enclosed in a cassette cartridge, this eliminates the need for dermal contact during normal use. Using any of the available exposure criteria for this solvent, we have concluded that there is no inhalation or dermal hazard associated with this ribbon.
[ILPI note: The 500 ppm limit and absence of IARC/NTP listings describe the historical correspondence. Current OSHA limits are 25 ppm (8-hour TWA) and 125 ppm (15-minute STEL); current carcinogen listings are explained in the assessment above. Exposure below a PEL alone does not waive HCS classification or communication.]
In light of the requirements of 29CFR1910.1200, we would like to market this ribbon with a maximum of 0.5% residual methylene chloride without a warning label or Material Safety Data Sheet. We would appreciate your review of our conclusion to ensure that it meets the intent of the Hazard Communication Standard. I would appreciate a written response to this inquiry. If you have any additional questions, please call me at (606) 232-2839.
Thank you.
ANDERSON, CIH
Staff Industrial Hygienist
The original official public domain version of this document is available from OSHA at https://www.osha.gov/laws-regs/standardinterpretations/1986-03-12.