Noise emissions from powered hand tools: A consumer alert!

Abstract

Existing standards for acquiring sound power levels of powered hand tools specify, for the most part, that sound levels be gathered in the unloaded test condition. However, there is an increase in sound level when the power tool is tested in the loaded condition. There are two purposes for gathering sound power level data: (1) determination of hearing loss hazard or irritation and (2) part of an engineering design optimization effort. The former is the focus of the National Institute for Occupational Safety and Health efforts. Sound power level data were gathered in the loaded and unloaded conditions from a variety of electrically powered hand tools. A model was then used to estimate the A-weighted sound pressure level at the operator’s ear from the A-weighted sound power (LWA) measurements of powered hand tools. The magnitude of LWA is found to be a reasonable predictor of the magnitude of sound pressure level exposure that a powered hand tool operator might experience across a variety of acoustical environments. This presentation explores the methods used to gather sound power levels, an evaluation of the model, and an examination of differences found between loaded and unloaded tool test conditions.