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.

November 13, 1997

Robert R. Lynch
OCAW Local 4-23
1500 Jefferson Drive
Port Arthur, TX 77642

Dear Mr. Lynch:

This letter is in response to your letter to Ray Skinner regarding ,the suitability of an electronic monitoring system for complying with the confined space standard (29 CFR 1910.146). Your letter was forwarded to the national office for a response.

The use of an electronic monitoring system is permitted by the standard. It is not intended to completely replace attendants, but to serve as an aid in the monitoring process. Its use does not automatically violate the standard, nor does it mean the employer is automatically in compliance with the standard. It is really a matter of how the device is used. Properly used, it can effectively increase the number of permit spaces a single attendant is able to effectively and simultaneously monitor. The use of such equipment can actually perform some of the attendant's duties better than the common practice of just having an attendant outside the space. Other duties, on the other hand, may need additional attendants to be properly satisfied.

All the duties described in paragraph (i) of the standard must be effectively performed for each permit space being monitored. Each confined space must be evaluated by the employer to determine the hazards that could exist for the entrant. If the space cannot be adequately attended by using a remote attendant, then added precautions or procedures must be taken to protect the entrant. Some situations may require another person or additional equipment to perform one or more of the attendants duties. The Product Bulletin you sent us addresses several of the limitations a single attendant may face when monitoring more than one space.

Proper training of the attendant becomes even more critical with the use of such a system. The attendant must be totally familiar with the use of the system and indicators or alarms that may alert him of a problem in the confined spaces. When such a device is used in a confined space program, its use and limitations must also be included in the training of the entrant and entry supervisors and the program modified to cover how any limitations will be addressed. Its effectiveness should also be included in the periodic evaluation of the program.

If you have any further questions, please contact Craig Moulton of my staff.

Thank you for your interests in safety and health.


John B. Miles, Jr.