Document ymMno9z87Bz4xnLOpMvDKwa93

Factors Influencing the Effective Life of Chainsaw Protective Legwear Mark J.M. Sullman, Liro Limited, P.O. Box 2244, Rotorua, New Zealand. email MEigmassey ac nz ABSTRACT In 1983, chainsaw cuts to the leg accounted for 29% of all reported lost time accidents in the New Zealand logging industry. The introduction of protective legwear reduced this figure to 8% in 1986. Since this time chainsaw cuts to the leg have continued to account for more than 5% of all injuries. There were several possible explanations for this failure to eliminate chainsaw cuts to the leg, including the deterioration of the protective legwear over time. Therefore, two research projects were established. The first attempted to find out how long the legwear was able to protect the user at the level required by the New Zealand Standard. This research found that the legwear failed after 6 months use by loggers working in New Zealand plantation forests. The second project was established to determine which factors caused the deterioration of the legwear's protective properties. This project found that exposure to even small quantities of oil resulted in the legwear comprehensively failing the New Zealand Standards test. Keywords: Chainsaw, protective legwear, cutresistant legwear, deterioration, chaps INTRODUCTION Cut-resistant legwear consists of many small strands woven into a matt-like material. Each protective garment contains 6-8 layers of this material. When the chainsaw cuts through the outer cover, the teeth in the chain grab these small strands, pulling them out of the garment and into the drive sprocket of the chainsaw. This clogs the chainsaw's drive sprocket and stops the chain from rotating. In New Zealand there are two types of cut-resistant legwear chainsaw trousers and chainsaw chaps. The trousers have protective material sewn inside to protect the front and side of the leg, with the outer material covering the back of the legs. Chaps contain protective material, which also cover the front and sides of the leg, but are open at the back to facilitate cooling. Figure 1 illustrates the proportion and number of all lost time injuries that were chainsaw cuts to the leg (a lost time injury is defined as an injury which causes a worker to miss the next scheduled full day's work). This shows an initial dramatic decline from 1983, where chainsaw cuts to the leg accounted for 29% of all reported lost time injuries, to 1986 where this figure was only 8%. This decline was attributed to the introduction and compulsory use of protective legwear [3]. Figure 1 also shows that from 1986 until 1994, chainsaw lacerations to the leg fluctuated between 6-11% of all reported lost time injuries. However, in 1994 the use of protective legwear with the S-mark was made compulsory in the New Zealand logging industry. S-Mark certification provides evidence that the legwear is certified to be of the level required by the New Zealand Standard [6]. The compulsory use of SMarked legwear resulted in a further small decrease in the number and percentage of chainsaw lacerations to the leg. Figure 1 shows that the introduction of cut-resistant legwear and the S-Mark did not totally eliminate chainsaw cuts to the leg.