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
Training certification requirements under the OSHA HAZWOPER. 1910.120
Training provisions of OSHA's HAZWOPER standard. 1910.38, 1910.120
Interpretation on medical surveillance requirements under OSHA's Hazardous Waste Operations and Emergency Response. 1910.120, 1926.65
Definition of a Hazardous Substance. 1910.120
The number of workers necessary to be present when there is a need for an operator to respond to a potential emergency that falls under the scope of the HAZWOPER standard. 1910.120
Worker protection for employees incinerating hazardous waste on cement plant property. 1910.119, 1910.120, 1910.1200
Training requirements under the HAZWOPER standard. 1910.120
Whether the OSHA HAZWOPER standard applies to the remediation of unexploded conventional ordnance at military sites. 1910.120, 1926.65
The requirement for change rooms whenever employees are required to wear personal protective clothing. 1910.120, 1910.141
Challenge Testing as a Substitute for Annual Refresher Training. 1910.119, 1910.269
OSHA's Hazardous Waste Operations and Emergency Response Standard. 1910.120
Interpretation of OSHA requirements for personal protective equipment to be used during marine oil spill emergency response operations 1910.120, 1910.132
Clarification on who must receive first responder awareness level training. 1910.120
The OSHA Hazardous Waste Operations and Emergency Response (HAZWOPER) regulation. 1910.120
The application of the OSHA HAZWOPER standard to employers of transfer facilities. 1910.38, 1910.120, 1910.120(a)(2)(iii), 1910.120(p), 1910.120(p)(8), 1910.120(p)(1)
OSHA PPE standard requirements for hazard assessment and employee training and the OSHA HAZWOPER standard requirements. 1910.120, 1910.132
Compliance with medical surveillance requirements for lead exposure during hazardous waste site operations. 1926.62
Response to IDLH or Potential IDLH atmospheres. 1910.134(g), 1910.120, 1910.156
OSHA guidance on Hazardous Waste Operations and Emergency Response (HAZWOPER) training. 1910.120
Clarification of the application of the Vinyl Chloride Standard and the Hazardous Waste Operations and Emergency Response Standard. 1910.1017, 1910.120