Noise declaration for hand-held machinery

A study on noise declarations and safety of hand-held machinery was executed in Finland in 1995–1996. Acceptable declarations were available for 77% of pneumatic and 94% of combustion-type machinery but only for 50% of electric machinery. This problem of machinery not having noise declaration can be corrected by national or international market control operations. For example, such a project on pneumatic hand-held machinery is going on in Finland by the occupational safety and health administration. The results will be presented at the beginning of 1999. Another problem is that the available noise declarations were usually correct but not necessarily valid. Laboratory measurements showed that declared values were correct, but the sound-pressure levels at the operator’s position were higher in practical use. For example, angle grinders’ declared idling SPLs were 80–86 dB, in a workshop they were 90–95 dB, and during metal processing the SPL was 110 dB. The reason for this is obvious: the quiet simulated, standardized operating conditions produce less noise than the typical use. The purpose of the system, the possibility to choose a low-noise machine, is partially lost. Too low declared values may also lead to false conclusions about the need of hearing protection.