Occupational Exposure to Wood Dust in the British Woodworking Industry in 1999/2000

摘要

Exposure to inhalable wood dust and compliance with the British Control of Substances Hazardous to Health (COSHH) Regulations 1999 were assessed at a representative cross-section of the British woodworking industry. Median exposures ranged from 1.5 to 2.8 mg/m3 across the selected industry groups, the lowest being in sawmilling and planing of wood. Overall, 27% of values exceeded the maximum exposure limit (MEL) at that time of 5 mg/m3. These results showed that the percentage of exposures above the MEL was less than in a survey carried out 10 years earlier. A wide variation of exposures was identified at different machines and tasks. At least 90% at bandsawing and cross-cut sawing were <5 mg/m3. In contrast, dust emission at circular sawing, sanding, cleaning and a miscellaneous group of activities was poorly controlled. Between 32 and 50% of results from these categories exceeded 5 mg/m3. The lower exposures in sawmills were largely attributable to the low usage of sanders and a group of circular saws, to the high use of bandsaws and moulders and to coarser dust from undried timber. Compliance with the COSHH Regulations was inadequate. Companies that claimed to have some form of written COSHH assessment were generally no more effective at controlling exposure to dust than those without an assessment. Similarly the ability of premises that provided information, instruction and training on the risks to health from wood dust and on measures to prevent or control those risks was not generally greater than in those that did not. Maintenance of local exhaust ventilation systems emerged as essential for achieving good control. Companies that followed both the statutory 14-monthly thorough examination and testing schedule and a weekly check system were more successful in this respect than those that did not. In spite of this, local exhaust ventilation alone provided insufficient dust control at several woodworking activities.