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.


March 25, 1985




SUBJECT: Applicability of 1910.212(a)(3)(ii) to Portable Pneumatic Powered Fastener Tools.


An interpretation pertaining to required safeguarding of portable pneumatic powered staplers and/or nailers used in general industry is provided in response to your February 21, 1985 request.

29 CFR 1910.212(a)(3)(ii) is applicable to heavy-duty portable pneumatic powered staplers and/or nailers. Section 1910.212(a)(3)(iv)(h) lists portable power tools as one type of machine which usually requires point-of-operation guarding.

29 CFR 1910.243(a)(2)(ii) and 1910.243(b) are the applicable general industry vertical standards for portable pneumatic powered tools. However, these standards are silent with regard to point-of-operation safeguarding. Under such circumstances, the OSHA Field Operations Manual (OSHA Instruction CPL 2.45), Chapter IV, permits the application of horizontal standards, such as 1910.212(a)(3)(ii), where employee workplace hazards exist. 29 CFR 1910.212(a)(3)(ii) is applicable to point-of-operation hazards associated with portable pneumatic powered staplers and/or nailers, and the safeguarding device shall be in conformity with any appropriate standards therefor.

The American National Standards Institute, Inc.(ANSI), and the International Staple, Nail and Tool Association (ISANTA) have recently published ANSI/ISANTA SNT-101-1983, Safety Requirements for Heavy-Duty, Portable, Compressed-Air-Actuated, Fastener Driving Tools. The standard, developed by an industry consensus group, is applicable to heavy-duty portable pneumatic powered staplers and/or nailers and is considered to be an appropriate standard within the meaning of 1910.212(a)(3)(ii). Publication of the standard has established industry recognition of the safeguards required. A copy of the standard is attached.

The ANSI standard pertains to portable pneumatic powered devices which drive fasteners made from material of cross sectional area equal to or greater than 18-gage per the American Steel Wire Gage (ASWG). (18 ASWG is equal to 0.0475 inch diameter wire, and ASWG was formerly Washburn & Moen or Roebling). Table 1, attached, itemizes the physical wire diameters relative to ASWG number.

The ANSI standard specifies that fastening devices which drive nails, staples, etc. and which utilize fasteners of 18 ASWG or greater shall be equipped with a "working-contacting elements" (interlocked pressure foot) for the prevention of accidental fastener discharges. The ANSI standard also specifies certain exceptions under which these pneumatic tools may be operated without a work-contacting element installed. However, only safeguarded pneumatic tools are acceptable to OSHA where hazardous employee exposures are substantiated. Unsafeguarded devices may be acceptable if an employer can demonstrate that the same degree of safety is provided by other means, or if safeguarding is not feasible and all other feasible means of protection are being utilized. (See Sections 4.3.4 and 4.3.5 of ANSI/ISANTA SNT-101-1983.)

It should be noted that the ANSI standard does not relate the requirement of a work-contacting element (interlocked safeguard) to the operating air pressure of the device, but rather to the size of the expelled fastener. Therefore, in general industry situations, prior interpretations (attached) which related 100-psi air pressure as a consideration, are not germane to heavy-duty portable pneumatic tools within the scope of the ANSI standard. Also, 29 CFR 1926.302(b)(3) is not applicable in general industry.

Tables 1 and 2, attached, are provided for the use of field personnel when evaluating the applicability of 1910.212(a)(3)(ii) to workplace situations in which portable pneumatic powered fastener tools are used.

[Corrected 3/23/2009]