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.

July 23, 1996

Dr. J. Nigel Ellis
Dynamic Scientific Controls
P.O. Box 445
Wilmington, DE 19899-0445

Dear Dr. Ellis:

This is in response to your May 6 letter addressed to Joseph A. Dear, Assistant Secretary, requesting several interpretations of the Occupational Safety and Health Administration (OSHA) standards regarding fall protection.

Your questions contain a mixture of issues and scenarios. In the spirit of satisfying your concerns, we will attempt to respond to the general question of how distance can be used to provide protection from fall hazards.

As you point out in your letter, the preamble to the new fall protection rule states in part, "OSHA has determined that there is no safe distance from an unprotected side or edge that would render fall protection unnecessary." However, when employees working 50 to 100 feet away from the unprotected edge have been properly trained, then the situation can be considered a "de minimis" condition. De minimis conditions are violations of standards that, for whatever reason, do not at the time of the inspection have an immediate relationship to safety and health and therefore are not included in a citation. As the distance between the worker and the edge diminishes, the hazard and likelihood of an accident happening, increases. Distance from a hazard is evaluated on a case-by-case basis. Factors determining violations of a standard and the issuance of citations can include, but not necessarily be limited to, the type of hazard and likelihood of injury, employee exposure, employer knowledge, and feasibility.

Your letter speaks of warning line systems and what appears to be controlled access zone (CAZ) situations. Provisions for warning line systems are found in 29 CFR 1926.502(f), and can be used in low slope roofing activities, but not on floors. CAZ requirements are found in paragraph (g) of the same section, and are also discussed in the section related to fall protection plans, paragraph (k). If, as your letter reads, "a contractor's employee wanders from the immediate area of work..." and is approaching the edge of an unprotected floor, then evidently the fall protection plan is ineffective. If individuals violate the procedures established in a fall protective system and fail to recognize the hazards of falling, then retraining may be necessary. Training requirements are found in 29 CFR 1926.503 (a), (b), and (c).

You questioned the need for both a warning line system and safety monitor on roots or floors more than 50 ft. wide. Once again, warning line systems are for those engaged in low sloped roofing activity. As addressed in 29 CFR 1926.501(a)(10), individuals involved in roofing work on low-slope roofs must be protected from falling when exposed to unprotected sides and edges 6 feet or more above lower levels. This section gives several means of protection, one of which is the combination of a warning line system and a safety monitoring system. The warning line system is in place to protect those working within its perimeter, and only at the time when workers are required to go beyond this system would the monitor be needed to perform those functions listed in paragraph (h). Should the working surface be a floor, the provisions listed in 29 CFR 1926.501(b)(1) would apply. Employers who satisfy the criteria for being able to use a fall protection plan may use a safety monitoring system, but only where the employer can demonstrate that it is infeasible or creates a greater hazard to use other conventional systems. OSHA emphasizes that safety monitoring systems are a last resort, as stated in the preamble standard (page 40715).

With regard to your question No. 5, an engineer's report submitted prior to work commencing could be used to satisfy the requirements of 29 CFR 1926.501(a)(2). The age of the report may not be relevant if conditions continue to be the same. However, one needs to consider the activity in the area since the time the report was written and any subsequent damage that may have occurred. If applicable to the situation, Subpart T, which addresses demolition activities, requires an engineering survey to be made by a competent person prior to permitting employees to start work.

Also, you reference relying on the owner's written opinion that the roof or floor is adequate for the intended work and use. Only if the owner fits the definition of a competent person, as defined in 29 CFR 1926.32(f), would their opinion satisfy this requirement. Contractors and owners may depend on each other's expertise in determining the strength and structural integrity of walking/ working surfaces, but the OSH Act made each employer ultimately responsible for the safety and health of his or her own employees. General requirements for inspecting the job site materials and equipment are in the existing 29 CFR 1926.20(b)(2), where as 29 CFR 1926.501(a)(2) is more specific. Frequency depends on the activity and potential hazards one may reasonably anticipate.

Thank you for your interest in job-site safety and health issues. Should all of your concerns not be addressed in this correspondence, we would welcome the opportunity to revisit a particular issue. If we can be of any further assistance, please contact:


Directorate of Construction - OSHA
Office of Construction Standards and Compliance Assistance
Rm. N-3621
200 Constitution Avenue, N.W.
Washington, D.C. 20210


Russell B. Swanson
Directorate of Construction