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.

February 28, 1991



Regional Administrator
[Directorate of Enforcement Programs]
SUBJECT: Use of Thermoplastic Pipe in Above Ground Locations


This is in response to your memorandum of January 17, concerning a recently issued [Safety and Health Information Bulletin (SHIB)] dated December 13, 1990, by the [Directorate of Science, Technology and Medicine]. The SHIB was issued in connection with the use of thermoplastic pipes in above ground transportation of compressed air or gases, and was based on the Plastic Pipe Institute's recommendation, dated December 1, 1989.

You indicated in your memorandum that various companies in your Region are misinterpreting the SHIB to imply that regular polyvinyl chloride (PVC) pipes that are designed to meet American Society for Testing and Materials (ASTM) Standard D1785-86, can be used for transportation of compressed air and gases. The SHIB, however, means that the pipes must either be constructed of or be encased in shatter resistant materials.

You requested an official citation issuance policy regarding the use of PVC pipes for above ground transportation of compressed air or gases. You also requested our office to describe a citation scenario.

Since PVC material does not possess shatter resistant property, and since it is very clear from the industry's recognized practice that PVC pipes are prohibited for above ground transportation of compressed air and gases (unless the pipelines are encased in shatter resistant material), any such use by the employers, where employees may be exposed to hazards, will be in violation of Section 5(a)(1) of the OSH Act. Therefore, employers who are found to violate the above described conditions or manufacturer's recommendations, during an OSHA inspection, shall be issued a 5(a)(1) citation.

For any further clarifications, please have your staff members contact [the Office of General Industry Enforcement at 202-693-1850].

[Corrected 10/22/2004]