Letters of Interpretation

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. Each 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.

These letters of interpretation and the standards they address may not apply to OSHA State Plans. State Plans are required to have standards and enforcement programs that are at least as effective as OSHA's and may have different or additional requirements. Please see OSHA-approved State Plans for more information.

NOTICE:

How to Request a Letter of Interpretation

Filters


Date Title Standard Number
Applicability of the Process Safety Management manufacturing processes involving workplace explosives. 1910.109, 1910.119
HHCs as it applies to strategic petroleum reserve storage sites. 1910.119
HHCs as it applies to end use applications of acrolein. 1910.119
Highly Hazardous Chemicals, methanol stored in an atmospheric tank. 1910.119
Scheduling and prioritizing on a "worst-first" basis. 1910.119
Coating processes covered by the PSM standard. 1910.119
Documentation establishing the boiling points or the 10 percent points of distillation. 1910.119
HHCs as it applies to Hydrogen Peroxide delivered from a tank truck. 1910.119
Processes involving flammable liquids and gases. 1910.119
Delivery of hydrogen peroxide, 52% by weight or greater. 1910.119
HHCs as it applies to Hydrocarbon fuels used solely for workplace consumption. 1910.119
Dimethylamine and Anhydrous Dimethlamine and the PSM standard. 1910.119
Sulfuric acid and the PSM standard. 1910.119
PSM Chemicals, unless specified, commercial grades less than 99 percent purity. 1910.119
Black liquor recovery boilers, associated oil (or gas) auxiliary fuel burner systems and PSM. 1910.119
Deadlines for completion of process hazard analysis. 1910.119
Refresher training requirements. 1910.119
Spray painting operations and the process safety management standard. 1910.119
Fumigants used to control insects in food plants. 1910.119
HHC's as it applies to flammable liquid stored at a worksite. 1910.119