Sofie E. Miller & Jacob Yarborough
Table saws, a category which includes bench, cabinet, and contractor saws, caused an estimated 54,800 blade-contact injuries in 2015. As a result, the Consumer Product Safety Commission (CPSC) has determined that there is an unnecessary risk of blade injuries from table saws, and is proposing a standard to limit this risk by requiring table saw manufacturers to “meet a performance requirement for table saws that limits the depth of a cut to the specified test probe, upon making contact with the saw blade at an approach rate of 1.0m/s, to 3.5 mm.
The proposed performance standards would require table saws to be equipped with an active injury mitigation (AIM) system, rather than a traditional passive protection (such as a blade guard) to achieve this risk reduction. An AIM system would detect human contact with the blade and stop its motion, as well as move it away from the operator. Using AIM technology a saw can detect contact with the blade through optical, thermal, electromagnetic, or ultrasound sensors. However, the only current technology to detect contact is through use of a closed electrical system that uses the body’s natural electric current to interrupt/complete/change the voltage of the closed system, which triggers a braking mechanism and stops the blade from rotating.
Technology to meet this performance standard is only available from two manufacturers, SawStop and Bosch. However, SawStop holds over 100 patents related to this technology, and is currently in litigation with Bosch to halt their sale of AIM enabled table saws.
To measure the benefits and costs of this rule CPSC first determined the societal cost due to table saw blade-contact injuries, and then defined the benefits as the reduction in these costs due to implementation of AIM systems. The Commission counted costs as the sum of the direct manufacturing costs, replacement part costs and the loss of consumer surplus due to increased prices and reduction in the number of saws sold.