Automatic restart of woodworking and metalworking equipment

January 31, 2005

Gary M. Genga

CY Concepts

[Recipient address omitted]

Dear Mr. Genga:

Thank you for your May 10, 2004 letter to former Assistant Secretary of Labor, John Henshaw. Your letter was referred to the Occupational Safety and Health Administration's (OSHA's) Directorate of Enforcement Programs. We replied to your inquiry on August 19, 2004, however certain information has come to our attention that requires us to modify our initial response. This correspondence reflects the most current information that pertains to your inquiry, and supersedes our previous reply. You had specific questions regarding the requirements for the protection against the unexpected restart of woodworking and metalworking equipment following an unscheduled electrical outage. Your paraphrased inquiries and our responses follow.

Question: Is low voltage, light-duty equipment (115-volt, single-phase), such as band saws, sanders, and drill presses commonly found in wood and metal shops, required to protect against automatic restarting upon restoration of electrical power following an unscheduled interruption?

Answer: As you may know, the OSHA standard for woodworking equipment is found at 29 CFR 1910.213. This standard, including the provision at 1910.213(b)(3) requiring the prevention of automatic restarting of dangerous woodworking equipment following the restoration of power after an unscheduled interruption, applies to woodworking machinery regardless of its electrical power supply voltage. Tools used in metalworking (with the exception of mechanical power presses) do not have the same explicit requirement in the OSHA standards for protection against automatic restart, but, as with all electric equipment used in the workplace, are generally required to be listed and labeled by a Nationally Recognized Testing Laboratory (NRTL). These NRTLs may have requirements addressing the issue of the prevention of automatic restarting in their listing and labeling criteria and testing protocols. If there are such requirements, OSHA has a provision, found at 29 CFR 1910.303(b)(2), that "listed or labeled equipment shall be used or installed in accordance with any instructions included in the listing or labeling."

Additionally, certain equipment-specific ANSI standards have requirements that restoration of power following an interruption not create hazardous conditions. Two such examples of this are ANSI B11.8-2001 American National Standard — Safety Requirements for Manual Milling, Drilling, and Boring Machines with or without Automatic Control and ANSI B11.10-2003 American National Standard for Machine Tools — Safety Requirements for Metal Sawing Machines with or without Automatic Control. The National Fire Protection Association (NFPA) Standard 79, Electrical Standard for Industrial Machinery (2002) also contains requirements for the prevention of the unintentional restarting of equipment following an interruption of power.1 National consensus standards often provide evidence of industry recognition of occupational hazards and of feasible means for abating the hazards.

Thank you for your interest in occupational safety and health. We hope you find this information helpful. 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. If you have any further questions, please feel free to contact the Office of General Industry Enforcement at (202) 693-1850.

Sincerely,

Richard E. Fairfax, Director

Directorate of Enforcement Programs

1 It should be noted, however, that this standard, NFPA 79, does not apply to fixed or portable tools that have been judged under the requirements of a NRTL. [ back to text ]