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 http://www.osha.gov.

April 1, 1981

Dr. John M. Hochstrasser
Tenneco Chemicals
Park 80 Plaza West - 1
Saddle Brook, New Jersey 07662

Dear Dr. Hochstrasser:

This is in response to your inquiry of February 23, 1981, concerning the requirements for respiratory protection in the regulated areas which you have established on the basis of a hazard presented by vinyl chloride. Please accept my apology for the delay in replying.

You indicated in your letter that you have designated certain areas as regulated areas, but that airborne concentrations of vinyl chloride are above the permissible exposure limits in these areas only when specific operations are being performed. It would appear that you are describing the type of operations that are defined as hazardous in the vinyl chloride standard. Specifically, in accordance with 29 CFR 1910.1017(b)(7), "'Hazardous operation' means any operation, procedure, or activity where a release of either vinyl chloride liquid or gas might be expected as a consequence of the operation or because of an accident in the operation, which would result in an employee exposure in excess of the permissible exposure limit."

29 CFR 1910.1017(l)(2) establishes that, "Areas containing hazardous operations or where an emergency currently exists shall be posted with legible signs bearing the legend: 'Cancer-Suspect Agent In This Area/Protective Equipment Required/Authorized Personnel Only.'"

The protective equipment required for hazardous operations is presented in 29 CFR 1910.1017(h), which reads:

(1) Employees engaged in hazardous operations, including entry of vessels to clean polyvinyl chloride residue from vessel walls, shall be provided and required to wear and use;

(i) Respiratory protection in accordance with paragraphs (c) and (g) of this section; and

(ii) Protective garments to prevent skin contact with liquid vinyl chloride or with polyvinyl chloride residue from vessel walls. The protective garments shall be selected for the operation and its possible exposure conditions.

(2) Protective garments shall be provided clean and dry for each use.

Signs would have to be posted and the protective clothing used only when "hazardous operations" are in progress. If you have instituted permanent signs where "hazardous operations" frequently recur, then you might want to consider providing covers which could be placed over and removed from the signs as the situation warrants.

I appreciate the opportunity to comment on your concerns. If I can serve you again, I shall be glad to do so.


Bruce Hillenbrand
Acting Director
Federal Compliance and State Programs