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.

July 25, 1979

Mr. Robert L. Zink
Attorney for SISCO, Inc.
One Cummings Point Road
Stamford, Connecticut 06904

Dear Mr. Zink:

This is in reference to our letter dated May 2, 1979, concerning your request for a variance from Section 1926.302(e)(7) Power Operated Handtools - Power Activated Tools, of the Safety and Health Regulations for Construction.

You have requested a permanent variance from Section 1926.302(e)(7) for an operation involving the use of power activated fasteners being driven into ductile cast iron ingot molds. You have stated that this operation is performed by your employees on a continuing basis for various steel companies.

The above standard (derived from ANSI A10.3-1970, Safety Requirements for Explosive - Activated Fastening Tools) prohibits driving power activated fasteners into hard and brittle material including cast iron. However, the latest ANSI standard concerning this subject (ANSI A10.3-1977, Safety Requirements for Power Activated Fastening Systems) has been modified to provide guidance on fastening into any questionable material. Specifically, ANSI A10.3-1977 paragraph 10.3 still contains the language prohibiting the fastening of hard and brittle materials including cast iron, but also refers back to paragraph 9.10 of the same standard. ANSI A10.3-1977 paragraph 9.10 states as follows:

       "Before fastening into any questionable material the operator
        shall determine its suitability by using a fastener as a
        center punch.  If the fastener point does not easily
        penetrate, is not blunted, and does not fracture the
        material, initial test fastening shall then be made in
        accordance with the tool manufacturer's recommendations (see

Our technical staff has thoroughly evaluated the data you submitted under date of April 30, 1979 which included a metallurgical report to show that the particular cast iron used in ingot molds is not hard or brittle and a laboratory report prepared by H.P. White Laboratories which concluded that the cast iron molds has sufficient malleability to permit power activated tool fastenings safely. It appears that your present method of fastening is acceptable. However, it is essential that all necessary safety requirements for this type of operation be observed including, but not limited to, appropriate personal protective equipment and proper barricading to isolate and protect your employees. Additionally, the appropriate laboratory testing (metallurgical) and center punch testing shall be made to assure that the metal characteristics of the ductile cast iron are receptive to a power activated fastener.

The enclosed Program Directive #200-67 has been issued to the Occupational Safety and Health Administration's (OSHA) field offices to provide guidance concerning de minimis violations. The Directive authorizes the use of de minimis violations in situations where OSHA standards (derived from such consensus groups as NFPA, ANSI, etc.) have been updated in later consensus publications in accord with new technology or equipment. However, the updated consensus standard shall provide equal or greater safety and health protection to the employees. A de minimis violation carries no penalty and no abatement is necessary.

From the information contained in your application, discussions with our technical staff, the Area Office and our solicitor, it has been determined that your present operation concerning fastening of ductile cast iron molds appears to meet the conditions of a de minimis violation under the terms of Program Directive #200-67 and ANSI A10.3-1977.

Affected employees and their authorized representatives shall be notified of our decision on your application in the same manner they were informed of your request for a variance.

Any further questions you may have regarding this matter may be addressed to our Area Director, U.S. Department of Labor, OSHA, 400 Penn Center Boulevard - Suite 600, Pittsburgh, Pennsylvania 15235, telephone: (412) 844-2905.

No further action will be taken on your request for a variance.


James J. Concannon, Director
Office of Variance Determination