VIBRATION DOSAGE FOR HANDHELD POWER TOOLS BASED ON EXPOSURE-RESPONSE RELATIONSHIP FOR WHITE FINGER DISEASE

Abstract

Power-tool vibrations can cause a variety of health disorders, ranging from inconsequential to disastrous. These vibrations may not be harmful when received in small doses but can cause vasospastic disorders, such as vibration-induced white finger disease (VWF), with frequent use or accumulated over time. Existing occupational guidance does not adequately describe the health risks associated with power-tool vibrations. In the current study, vibration levels for major brands of reciprocating saws and impact drivers were measured under typical use conditions, along with user comfort levels after different usage times. Results are provided in terms of acceleration and comfort levels as a function of usage time, varied grip-force conditions, and with or without use of gloves. Based on the VWF-incidence data from prior occupational studies, guidance on restrictions on usage of power tools is provided. It is found that existing ISO guidance for Europe overestimates allowable times, compared to those determined here.