May 14th, 2015 6:53 am ET -
Brian D. Lowe, Ph.D.; Stephen Hudock, PhD, CSP; Scott Earnest, Ph.D., P.E., C.S.P.; and Christine M. Branche, Ph.D., FACE
Recently, the American National Standards Institute (ANSI) released a revision to ANSI SNT-101, “American National Standard for Power Tools – Safety Requirements for Portable, Compressed-Air-Actuated, Fastener Driving Tools (ANSI SNT-101 2015
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(i.e., nail guns). NIOSH participated in the consensus process used to revise the standard. In all stages, NIOSH recommended changes that were consistent with the current scientific research about the safety risks attributable to nail guns, and interventions that are available to reduce them.
Despite NIOSH’s participation throughout the consensus process, the revised ANSI standard does not reflect current scientific research evidence and is therefore not sufficiently protective of workers. We encourage stakeholders to rely on NIOSH publications on nail guns for the most protective recommendations concerning nail gun safety.
On average, each year from 2001-2005, approximately 22,000 workers suffered injuries from pneumatic nail guns (PNGs) severe enough to require emergency department treatment. During the same period, approximately 14,800 consumers annually suffered injuries from nail guns that also were severe enough to require emergency department treatment.
The growth in PNG use and the alarming increase of traumatic injuries from 2001-2005 prompted NIOSH’s work on nail gun injury prevention. With the decline in residential building subsequent to 2006, and fewer construction workers using nail guns, the number of PNG injuries in the construction industry appears also to have declined.
It is less clear, however, whether the rate of PNG injuries (injuries per number of hours worked) in the construction industry has decreased. NIOSH prepared and published guidance on this topic for contractors, Nail Gun Safety: A Guide for Construction Contractors (co-branded with OSHA), and for workers, Straight Talk About Nail Gun Safety. Both documents are available in English and Spanish.
The revised ANSI standard makes minor improvements on the 2002 version, including providing definitions of nail gun actuation (trigger) systems, which has been modified to include additional explanation of the trigger systems.
A revision was needed because clear distinctions have emerged since 2002 in traumatic injury risks between different types of trigger systems. Release of the revised standard provides a timely opportunity to highlight critical safety-related considerations. NIOSH recommends that:
- Packaging, labelling, and/or product manuals for nail guns should clearly indicate, in plain language, that the full sequential actuation trigger (SAT) is the safest trigger. (http://www.cdc.gov/niosh/docs/2011-202/, page 2). Substantial evidence shows that the overall risk of nail gun injury is twice as high with a contact actuation (“bump”) trigger nail gun as with a sequential actuation trigger nail gun. We strongly encourage that PNG training emphasize this risk because we know also that an untrained worker is more likely to experience a nail gun injury than a trained worker. To comply with the ANSI SNT-101 standard, manufacturers must provide the safer sequential actuation trigger in the packaging with the tool. The standard has no requirement, however, that the manufacturer state, in plain language, that the SAT is the safer trigger. We believe that such plain language is a critical element of nail gun safety training and should be required. Some manufacturers have already included such plain language in the tool owner’s manual, but it is not a requirement under the standard.
- Coil nail guns should not be exempted from key trigger requirements. The revised ANSI SNT-101 standard exempts coil nail guns from the requirement that a sequential actuation trigger be provided. They are hybrid-industry tools that are used in the construction and manufacturing industries. Some coil nail guns can accommodate nails longer than 3.5 inches (which is equivalent to the length of nails used with framing nail guns), and the longer nails are known to be associated with greater injury severity. As such, the risks with many coil nail guns are equivalent to the risks of tools for which the trigger requirements apply. Given these factors of nail size and risk equivalence, there is no safety basis for exempting coil nail guns when used in construction from the requirement of including the safer trigger option.
- Nail guns should not be exempted from trigger safety requirements in any construction industry applications. The ANSI SNT-101 revised standard includes a construction activity (i.e., sheathing) in its definition of “production application.” There is no safety-based rationale for exempting any type of construction operation in the use of nail guns; therefore use of nail guns in construction should be specifically excluded from a definition of “production application.” In fact, some authoritative international guidelines have done this unequivocally. For example, the New Zealand Department of Labour (Guidelines for the Safe Use of Portable Mechanically Powered Nailers and Staplers, 2001, p 17) states, “Any tool that can drive a fastener that is more than 50 mm in length in any other sequence…” (other than sequential or restrictive nailing modes which preclude ’bump firing’) “…should be withdrawn and serviced to return it to its correct mode of operation if it is used on a construction site. If a nailer on a construction site cannot be modified to sequential trip, it should be withdrawn from service.” (bold added)