Table saw injuries: epidemiology and a proposal for preventive measures.

The table saw is a commonly used tool in both professional and hobby woodworking. Although there are a variety of models available, from portable table-top saws to professional-grade cabinet saws, all table saws have the same basic design: a flat surface through which a saw blade protrudes. The operator of the saw pushes the item to be cut toward and through the rapidly spinning blade. The potential for injury is evident. In addition to contact with the blade, saw operators may be struck by material being kicked back out of the saw or sustain eye or respiratory injuries due to rapidly flying sawdust and other debris. Modern saws have safety features designed to prevent injuries. Underwriters Laboratory 987 Standards for Stationary and Fixed Electric Tools requires that all new saws sold in the US have permanent riving knives to reduce kickback and modular blade guards.1 Riving knives have a barbed end that prevents materials being cut from being thrown back toward the operator. A blade guard is a clear plastic housing that completely covers the blade when not in use. (Figure 1) When an item is pushed toward the blade the blade guard rides up and over the item (Figure 2) and drops down to cover the blade again when the cut is complete. Blade guards prevent contact with the blade from the top, but cannot prevent contact to the front of the blade. Furthermore, the blade guard must be removed to make certain types of cuts. It can also hinder visibility so operators may remove it to make precision cuts. Removing the blade guard is not complicated but replacing it correctly can be time-consuming, requiring the use of tools. For instance, the owners’ manual for a Ryobi 10 in tabletop saw gives the following instructions for removing the blade guard and riving knife: “With the box end of the small hex wrench, loosen the two hex nuts at the base of the riving knife. Remove the riving knife/guard assembly. Retighten the two hex nuts on the base.” However, there are 7 separate steps involved in reinstalling and realigning the riving knife and blade guard assembly.2 This can lead to saw owners leaving the blade guard off permanently. Figure 1 Table saw with blade guard in place Figure 2 Blade guard action while cutting. Note that there is no protection from front-approach blade contact Saw purchasers receive an owners’ manual detailing not only the features and abilities of their new saws, but also safety information. The manual for the previously mentioned Ryobi 10 in saw contains 66 numbered safety points, 7 individual boxed warnings, labeled with the universal exclamation point in triangle symbol, and one illustration with a pun about eye injuries (“Foresight is better than no sight”).2 Even if one were inclined to read the entire owners’ manual, the sheer volume of safety information is overwhelming. Television programs, books, and websites also encourage safe saw usage behaviors, but users must seek this information out individually. Local woodworking clubs may provide instruction and training as well, but these may not be well-advertised. The current safety equipment and instruction is clearly not enough; table saw injuries are still regularly seen in emergency departments and hand surgery clinics. These injuries vary from simple lacerations to amputations and can cost millions in medical care and wage loss. Despite the frequent occurrence of table saw injuries, the topic has not been well explored in the literature. We performed a review of the literature to better describe the epidemiology of these injuries as well as current and future prevention measures.