Archive Notice - OSHA Archive

NOTICE: This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only.

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

August 18, 1995

Mr. Tom Bilodeau, M. Sc., P.Eng.
The Load & A-2-B Company
Neotrol Technical Services Ltd.
9411-63 Avenue
Edmonton, Alberta T6E OG2

Dear Mr. Bilodeau:

This is in response to your February 9 letter requesting an interpretation of an Occupational Safety and Health Administration (OSHA) standard addressing radio anti-two-block systems on cranes.

As you may know, OSHA does not approve nor endorse products. The variable working conditions at job sites and possible alterations or misapplication of an otherwise safe product could easily create a hazardous condition beyond the control of the manufacturer. However, when provided with adequate information, OSHA can offer an opinion as to whether or not the product affords compliance with certain regulations. We have reviewed the Radio Anti-Two-Block System information contained in your letter, and it appears that if the system automatically shuts down the hoist and/or boom lift mechanism in the event of a two-blocking incident, it would meet OSHA's anti-two-block requirements for cranes used to suspend personnel platforms.

If we can be of any further assistance, please contact me or Mr. Dale R. Cavanaugh of my staff at (202) 219-8136.


Roy F. Gurnham, P.E., J.D.
Office of Construction and Maritime