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 29, 1993

Mr. Jeffrey A. Shockey
Manager, Health & Safety
Compliance and Services Aluminum
Company of America
Alcoa Building
Pittsburgh, Pennsylvania 15219

Dear Mr. Shockey:

Thank you for your inquiries of November 2, requesting an interpretation of the Occupational Safety and Health Administration (OSHA) standard at 29 CFR 1910.179(n)(4)(i), Hoist limit switch, as it pertains to hoists that have two upper "hoist limit switches".

The OSHA standard in question requires that at the beginning of each operator's shift the upper limit switch of each hoist must be tried out under no load.

When the hoist is equipped with two upper hoist limit switches to prevent two-blocking, the first upper limit switch to be activated is the only upper hoist limit switch that needs to be tried at the beginning of each operator's shift. OSHA does not require a backup hoist limit switch.

We appreciate your interest in employee safety and health. If we can be of further assistance, please do not hesitate to contact us.


Roger A. Clark, Director
Directorate of Compliance Programs