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.

September 17, 1987

Mr. Frank L. Pellegrini
Law Offices
A Professional Corporation
Suite 400, Chouteau Center
133 South Eleventh Street
St. Louis, Missouri 63102

Dear Mr. Pellegrini:

This is in response to your letter of July 21 concerning the Hazard Communication Standard, 29 CFR 1910.1200.

Your questions and our responses are as follow:

Question 1:

Define target organs.


As defined in Casarett and Doull'e Toxicology, the Basic Science of Poisons, "Most chemicals that produce systemic toxicity do not cause a similar degree of toxicity in all organs but usually produce the major toxicity to one or two organs. These are referred to as target organs of toxicity for that chemical." Appendix A of the Hazard Communication Standard provides a target organ categorization of effects chemicals which have been found to cause such effects. The examples given are presented to illustrate the range and diversity of effects and hazards but are not intended to be all-inclusive.

Question 2:

After defining same, please advise where a manufacturer can obtain a list of target organs versus hazardous chemicals.


As stated in our June 29 letter, Appendix C of the standard provides a list of available data sources which can be used to determine the target organ effects of chemicals.

Question 3:

Define hazards of chemicals.


The Hazard Communication Standard defines "hazardous chemical" to mean any chemical which is a physical or a health hazard.

"Physical hazard" means a chemical for which there is scientifically valid evidence that it is a combustible liquid, a compressed gas, explosive, flammable, an organic peroxide, an oxidizer, pyrophoric, unstable (reactive) or water-reactive.

"Health hazard" means a chemical for which there is statistically significant evidence based on at least one study conducted in accordance with established scientific principles that acute or chronic health effects may occur in exposed employees. The term "health hazard" includes chemicals which are carcinogens, toxic or highly toxic agents, reproductive toxins, irritants, corrosives, sensitizers, hepatotoxins, nephrotoxins,agents which act on the hematopoietic system, and agents which damage the lungs, skin, eyes, or mucous membranes. Appendix A provides further definitions and explanations of the scope of health hazards covered and Appendix B describes the criteria to be used to determine whether or not a chemical is to be considered hazardous for purposes of the standard.

If I can be of further assistance, please feel free to contact me again.


Thomas J. Shepich, Director
Directorate of Compliance Assistance