• Standard Number:

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.

May 26, 1995

Mr. Scott Stratton
Vice President
Stratton, Inc.
2513 Deaton Street
Lake Charles, LA 70601

Dear Mr. Stratton:

This is in response to your September 8, 1994 letter requesting interpretation of the Walking-Working Surfaces Standard, 29 CFR 1910 Subpart D, as it may apply to the catwalks described in the workplace scenario below. Your questions and our reply follow. Please accept our apology for the delay in responding.

Scenario: An aircraft maintenance hanger has catwalks at approximately 38 feet (11.58m) and 58 feet (17.68 m) above the floor below. The lighting for the hangar which is suspended from the catwalk guard/handrails is well grounded and meets the National Electrical Code. The rails consist of 2 inches (5.08 cm) by 3 inches (7.62 cm) angle at the top and intermediate rails. The mounting bracket for each of the lighting fixture is attached directly to the top rail of the catwalk as depicted on the sketches: Detail l-El7 and Detail l-El9, enclosed with my letter.

Question 1: Does paragraph 1910.23(e)(6) apply to the catwalk described in the preceding scenario?

Question 2: Does this mounting method violate paragraph 1910.23(e)(6) which requires a clearance of not less than 3 inches (7.62 cm) between the handrail or railing and any other object?

Question 3: Are other brackets for catwalk lighting per sketches: Detail l-El7 and Detail l-El9 or the typical motorized (air, lighting, and receptacle) cable mounting reel per the sketch titled: Detail l-El5) subject to this paragraph 1910.23(e)(6) clearance requirement.

Reply: The catwalks described in the scenario above are considered runways as defined under existing paragraph 1910.21(a)(5). Runways are covered under existing paragraph 1910.23(c)(2). Under existing paragraph 1910.23(c)(2), elevated runways must be guarded by a standard railing. This requirement is intended to protect an employee using a runway from falling from an otherwise unguarded, elevated edge.

Standard railing requirements are covered under existing paragraph 1910.23(e)(1). Under existing paragraph 1910.23(e)(6), handrails and railings must be provided with a clearance of not less than 3 inches (7.6 cm) between the top railing and any other object. The source of these and other existing section 1910.23 requirements on guarding floors and wall openings and holes is the American National Standards Institute standard, ANSI A12.1-1967, Safety Requirements for Floor and Wall Openings, Railings and Toeboards. Paragraph 7.6 of ANSI A12.1-1967, which corresponds with existing paragraph 1910.23(e)(6), requires that all handrails and railings be provided with a clearance of not less than 3 inches (7.6 cm) between the handrail or railing and any other object.

In the subsequent 1973 revision of ANSI A12.1-1967, paragraph 7.6 was reworded by adding the adjective "stairs" in front of railing to identify specifically the type of railing to which the clearance requirement applied. Also, the clearance requirement was changed from 3 inches to one and one-half inches (3.8 cm). In preparing the proposed revision of 29 CFR 1910, Subpart D-Walking and Working Surfaces, the Occupational Safety and Health Administration (OSHA) reviewed the pertinent ANSI standards and determined that it was appropriate to limit the clearance requirement for handrails and stair rails. Also, OSHA determined that it was appropriate to adopt the one and one-half clearance required most recently in section 5.9 of ANSI standard A1264.1-1989. Accordingly, proposed paragraph 1910.28(c)(3), published in the Federal Register, Volume 55, Number 69 on Tuesday, April 10,1990, requires that the minimum finger clearance between handrails, including the top edge of stair rail systems serving as handrails, and any obstructions shall be one and one-half inches.

The first paragraph of the middle column of page 13375 of the preamble to the aforementioned proposed rulemaking (a copy of which is enclosed for your use) notes that proposed paragraph 1910.28(c)(3) "is consistent with the requirements of many local building codes, ANSI A12.1-1973,...."

In summary, the aforementioned proposed rule sets one and one-half clearance for handrails including the top edge of stair rail systems serving as handrails but it does not set clearance requirements for the top rail of a guardrail system. Please be advised that employer compliance with a proposed rule, in lieu of compliance with an existing rule, is considered a "de minimis violation," that is, a violation of an existing OSHA standard which has no direct or immediate relationship to safety or health. Such violations of the OSHA standards result in no citation, no penalty, and no required abatement.

Compliance with other OSHA safety standards which may apply must be determined for the particular workplace application. For example, existing paragraph 1910.23(c)(2) requires toeboards which meet existing paragraph 1910.23(e)(4) requirements wherever tools, machine parts, or materials are likely to be used on the runway such that they could fall, thereby potentially exposing employees to injury when working on the floor below.

We appreciate your interest in employee safety and health. If we can be of further assistance, please contact [the Office of General Industry Enforcement at 202 693-1850].


John B. Miles, Jr., Director
[Directorate of Enforcement Programs]

[Corrected 4/4/2005.

Note: On April 10, 1990 OSHA published proposed revisions to Walking and Working Surfaces; Personal Protective Equipment (Fall Protection Systems); Notices of Proposed Rulemaking; Slips; Falls; Trips in
Federal Register 55:13360-13441. It is available electronically only as an abstract. On May 2, 2003 OSHA reopened the rulemaking record on the proposed revisions to Walking and Working Surfaces and Personal Protective Equipment (Fall Protection Systems). It was re-published in its entirety in Federal Register 68:23527-23568 and is available electronically.]