Laboratories operated by employers that use small quantities of chemicals for quality control, research, or analysis may be exempt from PSM, but only if those operations are supervised by technically qualified individuals and are conducted in a properly equipped lab setting. OSHA has consistently held that a production-scale operation using HHCs cannot avoid PSM coverage by calling itself a lab. The exemption applies to bench-scale and pilot-scale analytical or R&D work, not to manufacturing processes that happen to take place near laboratory equipment. These letters address the boundaries of the exemption across a range of industry settings.

What OSHA Has Said

Feb 11, 2003
Laboratory Exemption for Pilot-Scale R&D Operations
OSHA addresses whether a pilot-scale chemical production unit qualifies for the laboratory exemption. OSHA finds that pilot-scale units that produce commercial quantities are not covered by the exemption.
Read OSHA Letter ↗
Apr 28, 1994
Lab Exemption Scope: Quality Control vs. Production
OSHA distinguishes between quality control laboratories (potentially exempt) and production operations conducted in a lab environment (not exempt). The focus is on the purpose and scale of chemical use.
Read OSHA Letter ↗
Sep 20, 1993
Early Guidance on Laboratory Exemption Applicability
Early OSHA interpretation establishing that the laboratory exemption requires both supervision by technically qualified individuals and the use of laboratory-scale quantities. Neither condition alone is sufficient.
Read OSHA Letter ↗

⚡ Key Compliance Takeaway

The lab exemption requires both scale and supervision. If your lab produces, repackages, or handles HHCs in process quantities, the exemption does not apply regardless of job titles.