Standard Interpretations - Table of Contents
• Standard Number: 1910.146(c)(5); 1910.146(c)(7); 1910.146(i); 1926.502(d)(15)

August 28, 1995

Christopher Seniuk M.P.A., C.S.P., C.I.H.
Assistant Vice President
Director of Safety and Health Services
Lovell Safety Management Co., Inc.
161 William Street
New York, N.Y. 10038-2675

Dear Mr. Seniuk:

This is response to the questions in your letter of May 10, 1995. The questions and responses are as follows:

Q 1.

Are attendants always required anytime employees enter a permit-required confined space (PRCS)?


The PRCS Standard allows entry into a PRCS without an attendant being present in two situations. They are:

1. when as per paragraph (c)(7) of 29 CFR 1910.146 all the hazards in the permit required confined space (PRCS) are eliminated, or

2. when as per paragraph (c)(5) of 29 CFR 1910.146 the only hazard in the PRCS is an actual or potential atmospheric hazard that can be controlled by continuous ventilation.

It is important that there be a understanding of what is meant by control of a hazard and elimination of a hazard. For purposes of the PRCS Standard, a hazard is considered to be controlled when the conditions which caused the hazard still exist in the PRCS but they are being continuously managed so that the hazard cannot reoccur. Elimination means the conditions which caused the hazard to be created no longer exist in the PRCS. The most common example of control of a hazard is use of continuous ventilation to prevent a hazardous atmosphere from being created. An example of elimination of a hazard is use of one of the techniques described in the definition of the term "isolation", which is defined in paragraph (b) of 29 CFR 1910.146. Generally speaking hazards are controlled or eliminated