Hazard warnings for chemical labels and mixtures

September 27, 1993

Mr. Michael Strong
Industrial Hygienist
Wacker Silicones Corporation
[Recipient address omitted]
Dear Mr. Strong:

This is a response to your letter of July 30, concerning the requirements under the Occupational Safety and Health Administration's (OSHA) Hazard Communication Standard (HCS), 29 CFR 1910.1200, for labeling provisions.

To follow are the two questions with answers in the respective order they were asked in your letter:

1. Does the hazard warning on the label have to exactly match the MSDS warning or can it be simplified? Further, what is the appropriate hazard warning for the listed examples?

OSHA's policy is that the hazard warning must be included on the label and must specifically convey the hazards of the chemical. OSHA has consistently maintained that this includes target organ effects.

The answers to the three examples in the order they were presented in your letter are: contact may cause eye damage, may damage the respiratory system, and may cause respiratory tract damage, respectively.

Appendix A of 29 CFR 1910.1200 clearly states that employees exposed to health hazards must be apprised of both changes in body functions and the signs and symptoms that may occur to signal the changes. The definition of "hazard warning" states that the warning must convey the hazards of the chemical and is intended to include the target organ effects. For example, if, when inhaled, the chemical causes lung damage, then that is the appropriate warning. Lung damage is the hazard, not inhalation.

Further, there are some situations where the specific target organ effect is not known. Where this is the case, the more general warning statement would be permitted. For example, if the only information available is an LC50 test result, "harmful if inhaled" may be appropriate.

2. If a raw material MSDS mentions the presence of a carcinogen such as ethylene oxide in "trace amounts" and we place a small amount in one of our products we should not have to refer to the trace of a trace on our MSDS and labels. Is my interpretation correct?

Labeling and MSDS requirements for Ethylene Oxide are specified in the Ethylene Oxide Standard (29 CFR 1910.1047(j)). In terms of container labeling section 1910.1047(j)(1)(ii) states that:

"The employer shall ensure that precautionary labels are affixed to all containers of EtO whose contents are capable of causing employee exposure at or above the action level or whose contents may reasonably be foreseen to cause employee exposure above the excursion limit, and that the labels remain affixed when the containers of EtO leave the workplace."

MSDS requirements in the Ethylene Oxide Standard are identical to those in the HCS section 1910.1200(g). If a hazardous chemical, such as Ethylene Oxide, is present in the mixture in reportable quantities (i.e., 0.1% for carcinogens, and 1% for other health hazards), it must be reported unless the mixture has been tested as a whole or unless the material is bound in such a way that employees cannot be exposed. If there is no exposure (and the standard defines exposure as including potential as well as measurable exposure by any route of entry), either under normal conditions of use or in a foreseeable emergency, then the chemical is not covered by the standard. Further, information must also be included on a MSDS for ingredients of a mixture present in concentrations of less than 1% (or 0.1% for carcinogens) when the hazardous substance may be released in a concentration which exceeds a PEL or TLV or may present a health risk to exposed employees.

We hope this information is helpful. If you have any further questions please contact [the Office of Health Enforcement at (202) 693-2190].

Sincerely,
Ruth McCully, Director
Office of Health Compliance Assistance

[Requester letter reproduced on OSHA page; omitted here.]

[Corrected 12/6/2024]