Occhealth Bulletin
09 August 2010
Reducing nail gun injuries among apprentice carpenters
Category: Reviews
Nail guns are typically used by construction workers and carpenters to drive nails and staples into wood or other building materials. Nail guns are widely available for both industrial and household (for Do It Yourself activities) use and are increasingly becoming popular as labor saving tools. But they are dangerous tools – there are approximately 35,000 visits to Emergency Departments each year as a result of injuries from nail guns.
There are two main types of nail gun, contact-trip and sequential, which are powered by a number of different sources including gases (butane or propane) or compressed air (pneumatic). The contact-trip tool discharges a nail when both the nose piece of the gun and the trigger are depressed. This allows rapid nail firing “bump nailing” to take place. The sequential trigger nail guns are considered safer to use as they require the nose piece of the gun to be depressed before the trigger is depressed in order to discharge a nail. This type helps to avoid accidental firing if the gun bumps against the worker or a colleague whilst the finger is on the trigger. Despite the fact that sequential trigger guns are safer to use there are currently no regulations in place requiring workers to use these tools.
Lipscomb and co-workers have recently published findings of their fourth year of follow-up on union apprentice carpenters. In the Mid-West, in 2008, 464 workers from two training schools were studied. Anonymous surveys were undertaken whilst the apprentices were in the classroom phase of their study. They were asked to report any nail gun injuries they experienced, the hours of nail gun use by triggering mechanism and the numbers of hours worked in residential carpentry over the year. The workers were also asked about the training they had received for safe nail gun use. The surveys were added to the surveys collected by the researchers in previous years: 2005 (n=654), 2006 (n=818), 2007 (n=490).
Following statistical analysis the researchers observed that the “apprentices experienced between zero and four nail gun injuries with a mean of 0.32 and a median of zero. Lifetime prevalence of injury was 22.6% and 12-month prevalence was 13%; both have declined steadily over time”. Injury rates also decreased in terms of hours of work in residential carpentry. The researchers have been able to determine that injury rates have declined 55% from baseline measures since the start of the study in 2005.
Lipscomb and co-workers had reported in their previous studies that access to early training programs and sequential-trip nail guns reduced injuries among the carpenter apprentices. The results of this study showed and supported this continuing trend. The apprentices, over time, had increased access to early safety training programs and tools with the sequential trigger mode of action. Although rates of injuries had declined in users of both types of nail guns in this study, injury rates were still reported to be twice as high for those using the contact-trip nail guns.
REFERENCE: Lipscomb, HJ., Nolan, J., Patterson, D. and Dement, JM. (2010) Continued progress in the prevention of nail gun injuries among apprentice carpenters: what will it take to see wider spread injury reductions? Journal of Safety Research Volume 41. pp241-245.