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 http://www.osha.gov.

October 27, 1995

Mr. James Sharpe
Consolidated Engineers Services
2345 Crystal Drive
Suite 1000
Arlington, Virginia 22202

Dear Mr. Sharpe:

This is in response to your letter requesting guidance in applying the 1910.146 - Permit-Required Confined Spaces (PRCS) standard to your workplace that is a multi-family residential and commercial building. Please accept our apology for the delay in this response.

For the purposes of clarity, we have restated your questions separately and answered them individually.

Question

Is a trap door or access panel considered a "portal through which a person can walk?" (This is referring to a portal that requires an employee to bend to enter.)

Answer

No. If an employee must bend down to avoid striking the top of an opening or step over a raised threshold, OSHA would consider the opening as restrictive to entry or exit. That is because the intent of the standard is to ensure that workers can exit a space quickly in emergency-type situations.

Question

Are cooling towers considered confined spaces?

Answer

We cannot categorically state whether all cooling towers fit the definition of a confined space since the term "cooling tower" covers such a broad category structures and configurations. Whether a cooling tower that meets the definition of a confined space is also a permit-required confined space it depends on whether there are potential or actual serious safety and health hazard(s) in the space at the time of entry. We note that cooling towers that are confined spaces would be permit (permit-required) spaces if there is exposure to moving parts such as fan blades, belts and pulleys. Where exposure to the moving parts can be permanently controlled through physical guarding, these hazards would not trigger the classification of the space as a permit space.

Question

Are attics considered confined spaces?

Answer

If an attic space in your building fits the definition of a confined space, then attics are confined spaces. However, attic spaces that are determined to be confined spaces should generally fall into the category of non-permit confined spaces because they have either natural or mechanical ventilation which would prevent accumulation of hazardous atmosphere and because other hazards would not normally be present.

Question

Are crawl spaces with or without trap door entry considered confined spaces?

Answer

How easily a worker can enter and exit a space is affected by both the size and type of ingress/egress point to the space (if there is a full doorway or only a small portal) and the actual transition (stairs, ladder, or nothing) into the space. To determine if a trap door were to render a space a confined space, you would look at considerations such as weight and swing of the trap door to see if they inhibit an employee from exiting the space. Even if the trap door itself does not impede entry/exit, if it is difficult to reach the trap door due to physical constraints such as piping, duct work, and conduits, then the crawl space would be a confined space.

The preamble to the standard discusses drop ceiling areas; that guidance should be followed for ascertaining whether a crawl space is a non-permit space (i.e., a space having either natural or mechanical ventilation to prevent accumulation of a hazardous atmosphere, and where other hazards are not present is not permit-required). Unlike attics, crawl spaces of the traditional multi-family or commercial building generally contain utility service lines (i.e., water, natural gas, fuel oil, sewage, steam and electric power) which pass through them. If these utility services do not terminate at end use equipment in the crawl space, the inherent hazards of the material flowing through the service lines do not have to be considered in the permit space determination unless there is reason to believe there is a reasonable probability of a rupture or leak where the contents of the piping would cause a serious safety or health hazard.

Question

Are soffit spaces considered confined spaces?

Answer

The confined space determination for a soffit should follow the logic found in the preamble discussion of drop ceilings.

Question

Are fan chambers and return air shafts served either by standard size doors or smaller openings confined spaces both when the heating, ventilating, and air-conditioning unit that serve these fan chambers and air shafts is operating, and when it is not?

Answer

For the purposes of this response, we assume that fan chambers and return air shafts are components of heating/ventilating/air conditioning (HVAC) equipment and not architectural spaces. A standard door is one in which a person, passing through the plane of the door, is not forced to enter or exit in a posture that might slow self-rescue, or makes rescue more difficult (i.e., stoop or bend over and/or step over a raised threshold).

HVAC equipment with a standard door would not normally be considered a confined space. HVAC equipment with access other than through a standard door would be considered a confined space. A confined space which has a hazard characteristic found in the definition of a permit-required confined space must be classified as such. The most likely hazards contained in the HVAC equipment components in question are mechanical (i.e., fan blades, chain and belt drives) and can be eliminated either through guarding or energy source isolation (lockout/tagout). In situations where all hazards can be eliminated through permanent guarding, a permit-required confined space may be classified as a non-permit confined space. Where the physical hazard of a permit space cannot be eliminated through permanent guarding, the permit space can be reclassified as a non-permit space under paragraph 1910.146(c)(7) once temporary (for the duration of the entry) measures are taken that eliminate the hazard. When entry into the confined space is required to accomplish guarding or energy isolation, full permit space entry procedures must be instituted until the hazard is eliminated.

With respect to 1910.146(c)(7)(iii) and when entry is accomplished by one employee who, is the evaluator, certifier, and entrant, not providing a certification document will be viewed as a de minimis violation (one in which no citation and civil penalty will be issued) under the following conditions.

1. The only actual or potential hazards in the space are electrical or mechanical.

2. The hazards of the space have been previously identified and the employee is trained on the hazards and the proper lockout methods.

3. The servicing employee has absolute control of the locks.

4. No additional hazards are introduced into the space.

Question

In the preamble (p.4475), OSHA states that drop ceilings are confined spaces, but adds that they are also examples of non-permit confined spaces because they are ventilated and do not present engulfment or other serious hazards. Does that mean no documentation of drop ceilings areas is required under (c)(5)(C) of the standard to establish that they are non-permit confined spaces?

Answer

An employer does not have to document that drop ceiling spaces in their workplace are non-permit confined spaces. The preamble concedes that, as spaces, drop ceilings can fit the definition of a confined space but normally will not contain a hazardous atmosphere or contain other serious safety or health hazards. However, when employers make the initial determination of their workplace required by paragraph (c)(1), drop ceilings that may contain hazards must be addressed. Further, where the ceiling void is a component of the building ventilation system (serving as plenum), atmospheric hazards of the work spaces below the ceiling must be considered in the evaluation of the drop ceiling void.

The reference to paragraph (c)(5) in the question is moot because drop ceilings without potential or actual hazards are not permit (permit-required) spaces. The requirements of (c)(5) deal only with the documentation necessary to establish alternate entry procedures for permit spaces which only contain atmospheric hazards. Thus it would apply if you had determined that a drop-ceiling void was a permit space because it did have potential or actual atmospheric hazards and you wanted to use the alternate entry procedures after controlling the atmospheric hazard through continuous mechanical ventilation.

The PRCS compliance directive is included as requested. If you have further questions on this response please contact Mr. Don Kallstrom in the Office of General Industry Compliance Assistance (202)219-8031. Again please accept our apology for the delay.

Sincerely,



John B. Miles, Jr., Director
Directorate of Compliance Programs

Enclosure: CPL 2.100 Preamble pg.4475

(For Enclosure, see printed copy)



August 5, 1994

Raymond Donnelly
U.S. Department of Labor
Occupational Safety and Health
Administration
Office of General Industry Compliance
Assistance
200 Constitution Ave., N.W.
Washington, D.C. 20210

RE: OSHA Confined Spaces Standard 1910.146

Dear Mr. Donnelly:

We request your assistance in classifying certain spaces as confined or not. Ours is a multi-family residential and commercial office building environment. Clearly we have some confined spaces, but they do not contain the complexity of potential hazards - if any at all - that would be expected in construction, manufacturing and industrial settings.

OSHA's three-part definition of a confined space is helpful in classifying some of our spaces; however, we have others that do not easily fit the definition. For some of our questionable spaces, we have been able to rule them out as confined based on OSHA's qualifier that spaces are not confined that have doorways or other portals through which a person can walk (see pp. 4477-4478 of the preamble). Equally helpful has been your qualifier that a space is not confined that is too small for complete bodily entry (p. 4477).

Some classification problems still remain, though. Specifically, is a trap door or access panel considered a "portal through which a person can walk"? I am referring to a portal that requires an employee to bend to enter. Are cooling towers considered confined spaces? Attics? Crawl spaces with or without trap door entry? Soffitt spaces? Fan chambers and return air shafts served either by standard size doors or smaller openings both when the heating, ventilating and air conditioning unit that serves these fan chambers and return air shafts is operating, and when it is not?

In the preamble (p. 4475), OSHA states that drop ceilings are confined spaces, but adds that they are also examples of non-permit confined spaces because they are ventilated and do not present engulfment or other serious hazards. Does that mean no documentation of drop ceiling areas is required under (c)(5)(C) of the standard to establish they are non-permit confined spaces?

If your answer if yes, does that mean the employer may make this judgement about any confined space without testing if the employer believes that the space does not contain or, with respect to atmospheric hazards, does not have the potential to contain a hazard capable of causing death or serious physical harm?

I have called OSHA seeking a copy of your directive on confined spaces for your compliance officers, but have been told one has not been written. If that information is erroneous, I would very much appreciate it if you could send a copy to me.

Your prompt assistance is greatly appreciated. I can be reached at 703/769-1151 should you wish to talk to me directly. Thank you in advance for your help.

Sincerely,



James Sharpe
Manager of Environmental Program