Standard Interpretations - Table of Contents
• Standard Number: 1910.244(b)

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

April 3, 2000

Mr. Andrew Logan, Jr.
The ArmaKleen Co.
469 N. Harrison St.
Princeton, NJ 08543

Dear Mr. Logan:

Thank you for your February 25, 2000 letter to the Occupational Safety and Health Administration's (OSHA's) [Office of General Industry Enforcement (GIE)]. You have requested an interpretation of 29 CFR 1910.244(b), Abrasive Blast Cleaning Nozzles, because you have, "...observed that the lower end model abrasive equipment did not appear to utilize dead-man switches as their control devices. Simple ball valves appeared in use."

Question: Is there an operational parameter in abrasive blasting under which a dead-man switch is not required?

Reply: The operational parameter about which you are inquiring is found in 29 CFR 1910.244(b), Abrasive Blast Cleaning Nozzles. The standard reads, "The blast cleaning nozzles shall be equipped with an operating valve which must be held open manually. A support shall be provided on which the