Monday September 09, 2019
Table Saws Reanalysis Could Put Need for NPR into Question
CPSC staff are seeking to research whether voluntary standards for table saws are reducing blade contact injuries. This would build on a project begun in 2017 on similar issues like gauging use of modular blade guards required in the standards.
A reason for the move is a discrepancy between findings in study (PSL, 11/26/18) and staffers' original assessment in the NPR (PSL, 1/3/17). If the former is true, it could "substantially reducing the net benefits for the proposed rule." Commissioner ballots were due at the PSL deadline.
The briefing package (bit.ly/2kgSvsT) explained:
"[T]he 2017 Study analysis indicates that, in 2017, the risk of injury on table saws manufactured with [traditional guards] was about seven times higher than the risk of injury on a table saw manufactured with a [modular guard]. If correct, a lower risk of injury on a table saw that meets the voluntary standard would imply that the voluntary standard is effective in reducing risk of blade-contact injuries on table saws."
The new work would involve both reanalysis of NEISS data and an exposure survey. Staffers wrote:
"This direct and detailed evaluation of table saws could confirm the estimates (of table saws in use) used in the 2017 Study, or could show if characteristics of table saw users, such as age or exposure, explain the apparent conflict between the results of the NEISS trend analysis and the 2017 Study. Such analysis would also allow staff to identify those factors that increase the risk that a user will be injured, including whether the [modular guard] required by the voluntary standard reduces the risk of blade-contact injury."
Earlier this year (PSL, 2/11/19), the Power Tool Institute pointed to the finding of the earlier study to assert that UL 987 is working, especially that just 12.2% of 2017 injuries were associated units with modular guards and that the injury risk was 7.19 time higher without modular guards.
The CPSC study found some 26,500 blade-contact injuries, attributing about 16,100 (60.7%) to bench saws, 7,000 (26.6%) to contractor, and 2,400 (9.2%) to cabinet. In most of the incidents – 88.9% versus 6.3% – the modular blade guards were not in use. But it also calculated that 57.4% of units in use during 2017 had the guards specified in UL 987.
CPSC's 2017 rulemaking seeks performance requirements to prevent blade-contact injuries. The goal is limiting the depth of cuts to 3.5 mm in tests with a finger surrogate and blades spinning 1 meter/second.
The activity is rooted in a 2003 petition that to mandate active injury mitigation systems (AIMS).
There have been patent disputes and concerns about setting design standards in the intervening years. CPSC held hearings and got comments in 2017. Commissioners then voted (PSL, 8/21/17) to continue with work that resulted in the study.