Construction hand tools: Vibration emissions from alternative inserts

Hand-arm vibration (HAV) is a workplace health hazard, emanating mostly from hand-held mechanical tools, and from which prolonged exposure can cause severe medical conditions. HAV represents a particular risk within construction that relies extensively on these types of tool. Since becoming a legal requirement throughout the European Union for employers to manage vibration risks, construction managers must (inter alia) assess workers' vibration exposure. Here two specific problems confront them: a dearth of vibration emission data relating to construction tools; and the 'irrelevance' of much data currently available (due to their not being measured under real work conditions). To help address these shortcomings, emission data were measured according to ISO 5349 and analysed in respect of several hammer-action and percussive tools of varying types and weights, while using different sizes of tool inserts. Some additional measurements were also carried out on materials of different hardness. Results show that HAV emissions vary among differing tool insert sizes, albeit 'regular' patterns of variance were not found. Larger insert sizes did tend to emit larger vibration emissions; and this coupled with increased operator time exposure (per unit of work done) with such inserts represented a greater HAV risk. These characteristics, combined with observed emission variance among similar tools of different weights and working upon different materials, help provide construction managers with a broader pool of data with which quantitative HAV exposure assessments may be carried out.