[Updated 9/21/11: see below]
Ka-chunk, ka-chunk, ka-chunk, ka-chunk, ka-chunk……is the familar sound around house framing and roofing jobs of the pnuematic nail gun. !Expletive! Expletive! Argh….Expletive!….is the cursing yelps from guys whose fingers, hands, and other body parts are punctured by nails inadvertently shot from these construction tools. An estimated 37,000 individuals in the US are treated annually in hospital emergency rooms for nail gun injuries. Moreover, nail guns are responsible for the most tool-related hospital admissions for workers in the construction trades. About 98 percent of the cases involve males, and it’s a 60-40 split between workers and consumers (e.g., weekend do-it-yourselfers) who sustain the puncture injuries. Kane Guthrie at Life in the Fast Lane offers some gruesome photos of nail-gun injuries from his emergency department in Australia.
Hester Lipscomb, PhD and colleagues have conducted numerous studies examining risk factors for nail gun injuries (here, here, here, here. ) The latest is a qualitative assessment of the hardware store sales personnel’s understanding of both the injury risk for nail gun users and the safety differences between the two trigger mechanisms. (The most common—a “contact” or “bump fire” trigger—allows the nail to discharge anytime the nose and the trigger mechanism are both depressed. The newer “sequential” design requires the nose be depressed before the trigger is engaged which makes it more difficult to unintentionally discharge nails.) Sixty-eight percent (68%) of nail-gun related emergency room visits involved those with “contact-triggers,” according to an analysis by the Consumer Product Safety Commission.
The researchers approached sales people in 217 stores (building supply, home improvement, lumber yards, tool outlets) in six States as if planning to buy a nail gun. They gave the sales people a chance to provide information about the tool’s safety features, and if it wasn’t offered, the researcher asked questions like:
“I have heard there are differences in the triggers on these tools. Can you tell me anything about those?”
The authors report their findings “Buyer beware: Personnel selling nail guns know little about dangerous tools” in the August 2011 issue of the American Journal of Industrial Medicine. Overall, only 41 percent of the 217 salespeople provided the shopper-researcher with any safety information and only 24 percent mentioned any difference in the trigger mechanisms. Sixty-two percent of the sales people indicated they’d used a nail gun, and those individuals were nearly three times more ilkely to provide safety information to the shopper-researchers. The researchers report on the full-range of good and bad advice provided by the store employees. In the category of appropriate safety information, the researchers heard:
“brace parts to be nailed without putting body parts in the line of fire,”
“use only nails designed for tool being used and the job being done,”
“avoid speed when working with the tool,”
“avoid knots in the wood, other nails, or metal attachments (such as joist hangers) as we were nailing since they could cause nails to ricochet”
It was more common however for the sales people to provide incorrect information; it happened with 74% of them. The authors heard the following:
“No training is necessary; you just have to get used to how it feels.”
“You would have to be an idiot to shoot yourself with one of these.”
“No way you can hurt yourself with these. They don’t fire like a gun. You have to have the nose pressed down to fire so there is no way you can shoot yourself.”
The authors note that this latter comment
“fails to acknowledge that a tool with contact actuation held with the trigger depressed will fire a nail into anything the nosepiece touches whether that is a board, the user’s thigh or another person.”
The authors’ conclusion is that at the present time, contractors, do-it-yourselfers, and other users of pneumatic nail guns should be cautious about relying on the typical sales person to describe accurately the safety risks of this popular piece of equipment. They suggest, however, that points of sales (and rental) locations for construction tools could serve as “excellent potential venues to influence” the tools selected and the safety attitude conveyed to customers (users) of it.
[9/21/11 Update: OSHA and NIOSH issued a publication “Nail gun safety: a guide for construction contractors.” ]