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 8, 2012

Mr. John Elskamp
Superior Powder Coating, Inc.
600 Progress Street
Elizabeth, New Jersey 07201

Dear Mr. Elskamp:

Thank you for your letter dated August 16, 2011, to the Occupational Safety and Health Administration (OSHA) for a clarification of OSHA's Permit-Required Confined Spaces standard, 29 CFR 1910.146(c)(7). [1] This constitutes OSHA's interpretation only of the requirements discussed and may not be applicable to any question not delineated within your original correspondence.

Your scenario and questions are paraphrased and our responses follow.

Scenario: In my employer's facility, we have open top tanks used for cleaning parts. The various baths range from 40 to 72 inches deep; the widths range from 3-8 feet and the lengths from 9-12 feet. The tanks all have external valves to turn off the incoming water, which is locked out in accordance with OSHA's "The control of hazardous energy (lockout/tagout)," 29 CFR 1910.147. Further, the tanks drains are also operated externally. In addition, the tanks have tested negative for an IDLH atmosphere and the oxygen content is in the acceptable range.

Question: Would these permit-required confined spaces qualify for reclassification to non-permit spaces under 29 CFR 1910.146(c)(7)?

Reply: Based on the scenario that you describe, a permit-required confined space can be reclassified as a non-permit required confined space if it does not contain any actual or potential hazardous atmosphere and all hazards within the space are eliminated. We assume there are no hazardous atmospheres or a potential for a hazardous atmosphere from the process of cleaning parts in these tanks. The engulfment or drowning hazard would need to be eliminated. You state that there is an isolation valve outside of the tanks that you are able to close and apply a lockout device to prevent water from going into the tank while employees are inside. The hazard would be considered eliminated only by use of the techniques described in the definition of the term "isolation," which is "the process by which a permit space is removed from service and completely protected against the release of energy and material into the space by such means as: blanking or blinding; misaligning or removing sections of lines, pipes, or ducts; a double block and bleed system; lockout or tagout of all sources of energy; or blocking or disconnecting all mechanical linkages" per OSHA standard 29 CFR 1910.146(b). By applying the lockout device to the closed valve, you would have eliminated this hazard and may reclassify the space as a non-permit space as long as the hazard remains eliminated.

Thank you for your interest in occupational safety and health. We hope you find this information helpful. Please be aware that OSHA's enforcement guidance is subject to periodic review and clarification, amplification, or correction. Such guidance could also be affected by subsequent rulemaking. In the future, should you wish to verify that the guidance provided herein remains current, you may consult OSHA's website at www.osha.gov. If you have any further questions, please feel free to contact the Office of General Industry Enforcement at (202) 693-1850.


Thomas Galassi, Director

Directorate of Enforcement Programs


A space classified by the employer as a permit-required confined space may be reclassified as a non-permit confined space under the following procedures:


If the permit space poses no actual or potential atmospheric hazards and if all hazards within the space are eliminated without entry into the space, the permit space may be reclassified as a non-permit confined space for as long as the non-atmospheric hazards remain eliminated.


If it is necessary to enter the permit space to eliminate hazards, such entry shall be performed under paragraphs (d) through (k) of this section. If testing and inspection during that entry demonstrate that the hazards within the permit space have been eliminated, the permit space may be reclassified as a non-permit confined space for as long as the hazards remain eliminated.

NOTE: Control of atmospheric hazards through forced air ventilation does not constitute elimination of the hazards. Paragraph (c)(5) covers permit space entry where the employer can demonstrate that forced air ventilation alone will control all hazards in the space.


The employer shall document the basis for determining that all hazards in a permit space have been eliminated, through a certification that contains the date, the location of the space, and the signature of the person making the determination. The certification shall be made available to each employee entering the space or to that employee's authorized representative.


If hazards arise within a permit space that has been declassified to a non-permit space under paragraph (c)(7) of this section, each employee in the space shall exit the space. The employer shall then reevaluate the space and determine whether it must be reclassified as a permit space, in accordance with other applicable provisions of this section.