I have visited and wood recycling facility in order to evaluate employees’ exposure levels to wood dust. The facility was mostly processing mostly packaging wood products into shredded wood mixes of various qualities for the wood board manufacturing industry, agricultural industry or for use as a bio-fuel. The site processed up to 6 thousand pallets per week but the total number was variable depending on order quantities. The final products were temporarily stored on site. The site consisted of a large storage building for high grade products and a maintenance/office building.
The site processed mixed (hard & soft) waste wood products with the vast majority of the product being soft wood. The main hazardous substance employees could be exposed to was inhalable wood dust. Both Hard and Soft wood dust have workplace exposure limits (WEL) set to 5 mg/m3 averaged over an 8 hour working period. In addition to this the hard wood dust has “carc & sen” and soft wood has “sen” designation which means it has the ability to cause cancer and/ or occupational asthma.
The low grade material were unloaded on one end of the site where they were continuously loaded into a large wood shredder. The shredded material was that transported via powerscreen separator and deposited on the ground. An operator working on a JCB loader either transported the deposited material to a storage area or loaded it onto transport lorries.
All the activities being carried out on site such as unloading, shredding, transporting to storage and loading had the potential to generate significant quantities of wood dust. The main control measures of site were wetting of the materials prior handling and shredding using semi enclosed and enclosed shredding machines. Operatives working with the machines were also protected by installed cabin air filtration systems.
The wood dust air monitoring results suggested that the employees were unlikely to be exposed to significant levels of wood dust. None of the personal exposures exceeded the level above which the wood dust would be considered to be hazardous. I have concluded that due to the low exposure level of employees, formal health surveillance program was not necessary.