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.

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Date Title Standard Number
Guardrail height when used as fall protection for work surfaces with two elevations. 1926.502(b)(1)
The difference between maintenance and construction;scaffold inspection requirements; and definition of periodic scaffold inspection. 1910.28, 1910.12, 1926.451(f)
Scaffold stairs used for access to floors during construction of multistory buildings. 1926 Subpart X
Using combinations of respiratory protection not approved by NIOSH. 1910.134(d)(1)(ii), 1910.94(a)(5)
OSHA does not have authority over consumer safety. 1975.3
Injury and illness recordkeeping: job rotation or transfer for musculoskeletal disorders. 1904 - Table of Contents
Comparing medical evaluation requirements in the HAZWOPER, Respiratory protection, and Fire brigades standards. 1910.120(f), 1926.65(f), 1910.134(e), 1910.156(b)(2)
Trainer accessibility during training. 1910.1030, 1910.1030(g)(2)(vii)(N)
When to use quantitative and qualitative fit testing. 1910.134(f), 1910.134 App A
Citation policy regarding automatic sprinkler systems. 1910.252(a)(2)(vi)(B)
The grimace step in respiratory protection fit-testing procedures. 1910.134(f), 1910.134 App A
Correct placement of air sampling cassettes on abrasive blasters. 1910.94(a)(2)
Respiratory protection: editing the medical questionnaire; medical questionnaire not always required. 1910.134(e)(2), 1910.134 App C
Clarification of a PLHCP under the Respiratory protection standard. 1910.134(e)
Acceptability of western style hard hats. 1926.100, 1926.95
Definition of "in storage" and clarification of the requirements for intermittent use of gas cylinders. 1926.350(a)(10)
Clarification of respirator costs, annual training, and "effective" seal checks. 1910.134(c)(4), 1910.134(f)(2), 1910.134(g)(1)(iii), 1910.134(k)
Proper installation of presence sensing devices for mechanical power presses. 1910.217(c)(3)(iii)
Misprint in 1998 Edition of CFR: Methylene Chloride Standard. 1910.1052(g)
OSHA access to personally identifiable medical records (HIV test results). 1910.1020(e), 1913.10