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.

April 22, 1999

Mr. Eric C. Brett
Corporate Safety Manager
Hitchiner Manufacturing Co., Inc.
Milford, New Hampshire 03055

Dear Mr. Brett:

This is in response to your letter of October 30, 1997, regarding the application of the Occupational Safety and Health Administrations's (OSHA's) standard, 29 CFR 1910.111, as it applies to the transfer of ammonia.

As you stated in your letter, "according to §1910.111, the employer shall require the continuous presence of an attendant in the vicinity of the operation during such time as ammonia is being transferred." You also stated, "it is clear that the employer must ensure that an attendant is present continuously during the transfer of ammonia from the truck to the stationary tank. However, it is not clear as to whether or not the vendor performing the off loading could be considered the attendant." Further, you indicated that the Department of Transportation (DOT) has regulations which define the role of qualified attendant.

Please be advised that DOT requirements apply during the transfer from the vehicles to storage tanks on site. OSHA has no jurisdiction during this portion of the operation. On the other hand, transfer from the storage tanks to reaction tanks on site, for example, must comply with OSHA's standard §1910.111.

In your letter, you inquired whether the vendor could be classified as an attendant. We interpreted the "vendor" in your question to be the person unloading the vehicle to storage tanks; and for that part of the transfer, as mentioned previously, DOT standards would apply and not OSHA's.

On the other hand, an attendant that would be present for the transfer from the storage tanks to the other tanks on site, would be a person who is familiar with the appurtenances, as to their proper operation and function, and one who is trained in handling emergency situations.

Thank you for bringing you concerns to our attention. If you need further assistance, please contact Alcmene Haloftis of my staff at 202-693-1850.


Richard E. Fairfax, Director
Directorate of Compliance Programs