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.

December 20, 1994

Mr. David R. Jones Loss Control Manager Smith International, Inc. 16740 Hardy Street Houston, Texas 77035

Dear Mr. Jones:

This letter is in response to your variance application of November 11 addressed to the Assistant Secretary of the Occupational Safety and Health Administration (OSHA), and forwarded to the Directorate of Technical Support for action. In this variance application, you requested a permanent variance from 29 CFR 1910.212(a)(1), the standard which defines OSHA's general machine-guarding requirements.

You will notice that this standard requires that machine guards be provided to protect employees from several identified hazards (e.g., points of operation, ingoing nip points), but does not specify the type of machine guard that an employer must use. The standard recommends several types of machine guards, including barriers, tripping devices, and electronic safety devices, but leaves to the employer the decision regarding which machine guard best suits the working conditions. By not specifying the types of machine guards that must be used, this standard is referred to as a "performance" standard (i.e., the employer is free to adopt a machine guard that "performs" in such a manner as to meet the standard's objective--to protect employees from the identified hazards). If OSHA had specified the types of machine guards that must be used, the standard would be a "specification" standard.

The purpose of a variance is to allow an employer to adopt an alternative other than one specified by OSHA in a standard (i.e., to vary from an OSHA specification standard). If OSHA does not specify the means by which an employer is to control hazards, and instead permits any protective alternative to be used by an employer (as is the case under 29 CFR 1910.212[a][1]), no need exists for a variance. Under this standard, therefore, you are expected to use or develop an alternative machine guard that will provide your employees with protection from the identified hazards.

Alternative machine guards may be adopted from industry practices (i.e., machine guards) used under similar working conditions or machine guards recommended under industry consensus standards, or the machine guards may be devised using a unique, custom design. In your case, in which commercially available machine guards have been found to be incompatible with a manufacturing process, construction of a custom machine guard appears to be necessary. Custom machine guarding is most readily accomplished through the application and use of work-positioning/holding fixtures. These fixtures generally result in improved product quality, as well as increased production. You should note that the machine guard need not be located at the point of operation, but only designed to prevent your employees from coming in contact with the point of operation (e.g., a hood that covers the frame or blade). Also, while the steps you've taken to protect your employees (i.e., proper procedural training, equipment orientation, limited use of the hacksaw, the location of the work process, and configuration/motion of the reciprocating frame) are commendable and important to their overall safety, these steps are not considered by OSHA to be acceptable alternatives to properly designed machine guards.

If you desire technical assistance from OSHA on this matter, please contact Mr. Gerry Bailey at our Dallas Regional Office at (214) 767-4731. If you have any questions regarding this letter, you may telephone Ms. Juanita Jones or Mr. Roger Stephens at (202) 219-7193.


Charles E. Adkins, CIH Director Directorate of Technical Support