March 4, 2014
Washington, DC 20005
Re: Request for Interpretation of OSHA's Amended Hazard Communication Standard (HCS 2012) about Hazards Not Otherwise Classified
Dear Mr. B***:
This letter is being issued to API to provide additional guidance on how to apply the requirements for Hazards Not Otherwise Classified (HNOC) under the March 26, 2012, revisions to OSHA's Hazard Communication Standard (HCS 2012).
Under OSHA's Hazard Communication Standard, an HNOC is defined as follows:
an adverse physical or health effect identified through evaluation of scientific evidence during the classification process that does not meet the specified criteria for the physical and health hazard classes addressed in this section. This does not extend coverage to adverse physical and health effects for which there is a hazard class addressed in this section, but the effect either falls below the cut-off value/concentration limit of the hazard class or is under a GHS hazard category that has not been adopted by OSHA (e.g., acute toxicity Category 5).
29 C.F.R. § 1910.1200(c).
Classifiers may rely on the following guidance in applying the definition of an HNOC under HCS 2012:
- An adverse physical or health effect is a material impairment of
health or functional capacity, as that phrase is used in section 6(b)(5)
of the OSH Act, 29 U.S.C. § 655(b)(5), resulting from workplace
exposure to a chemical.
- A health effect is determined in accordance with the weight of evidence criteria in A.0.3.
- The term physical effect generally refers to a material impairment of health or functional capacity caused by the intrinsic hazard(s) of a particular chemical in normal conditions of use or foreseeable emergencies. Scalds caused by exposure to chemicals at high temperatures, and slips and falls caused by treading on a solid chemical shaped in a rounded form or spilled liquids are not covered physical effects under the HNOC definition. By way of example, water is not classified as an HNOC merely because an employee might be scalded by contact with boiling water or because an employee might contract hypothermia by being immersed in cold water for a long period of time. Similarly, water is not classified as an HNOC by virtue of the fact that an employee might be injured when slipping and falling on a wet surface or when sprayed by water at high pressure. The foregoing examples of adverse physical effects that are outside the scope of HNOCs are designed to assist in better understanding the concept of HNOCs. They are not intended to be exhaustive or limited to chemicals, such as water, which are not hazardous chemicals.