Wood dust exposure

25 November 1994

Background

At Monash University, a number of staff are exposed to wood dust. At most campuses there are woodworking areas where a variety of activities generate wood dust, including sawing, sanding, planning, routing, etc. The woods worked include a variety of particle boards, soft timbers, treated pine, masonite, plywood and various imported and Australian hard and soft woods. The size of the dust particles produced, the amount of dust and resultant exposure to staff working in these areas depends on a number of factors including the equipment being used, the ventilation and extraction system in place, the state and type of timber, general ventilation in the area and any personal protective equipment that may be used.

Possible health effects

1. Dermatitis

Skin irritation or dermatitis can arise from either the direct mechanical action of rough timber, chemical irritation from either the timber itself or chemicals used to treat the timber or as a result of sensitization or the development of allergic problems related to the timber or the chemicals used to treat this. It is also possible that the dermatitis may arise from a combination of the above effects. The skin problems can usually be managed by changes to the working practices including the use of protective gloves. If it occurs, dermatitis amongst carpenters and woodworkers is normally mild as it can usually be effectively managed. If problems arise, contact the University's Consultant Occupational Physician at Occupational Health, Safety & Environment who can enable the problem to be investigated and appropriate steps taken.

2. Allergic respiratory effects

A number of timbers have been implicated in causing an asthma type problem in wood workers. This may occur in association with an allergic dermatitis. The most common timbers causing this problem are western red cedar and oak though many other timbers have been implicated. Symptoms of shortness of breath, wheezing and coughing may develop many years after exposure first started. Typically, the symptoms worsen during the working week and subside or disappear during long weekends and holidays. Such cases need to be managed very actively as the condition usually worsens. Cessation of exposure is often required to effectively treat individuals affected by this condition and this may require new work duties or a change of job or trade.

3. Mucosal and non-allergic respiratory effects

Several studies have been published indicating a reduction in lung function for workers exposed to wood dust over a long period. There are still some questions being asked about whether these studies are accurate and reliable. Many wood workers report nasal symptoms including nasal discharge, blocked nose or sinus trouble related to their exposure to general dust. Some studies have shown some changes to the lining of the nose, which could in part be related to the symptoms.

4. Carcinogenicity

In the late 1960's an association was first noticed in the furniture industry in the United Kingdom between nasal adenocarcinoma (a rare type of nasal cancer) and wood workers in the furniture industry. Further studies in other countries have confirmed an excess of such tumours amongst furniture workers mainly working with hardwoods. Considerable time and effort has been directed towards clarifying the exact cause of this increased risk of cancer to enable appropriate control measures to be put in place. A recommended exposure limit for hardwood dust of 1 mg dust per cubic metre of air has been adopted as a threshold limit value (TLV) in Australia. For softwoods or particle board, a general nuisance dust limit of 10 mg dust per cubic metre of air is currently in place.

5. Associated chemicals

Concern has been raised about certain chemicals used in the manufacture of timber products like particle board and as preservatives. Of these chemicals, formaldehyde is the most frequently mentioned as a potential problem. Exposure to formaldehyde can cause irritation to the eyes and nose and more rarely allergic skin and lung problems. Treated timbers that are wet with preservative solutions should only be handled with impervious coveralls, gloves and boots. Exposure to wood dust and vapours (that may be generated by using power tools or machinery on treated timber) should be avoided by the use of local exhaust ventilation or personal protective equipment. After handling treated timber, the hands and face should be washed with soap and water before eating, drinking or smoking.

Recommendation

Where staff is concerned about dust and chemical exposure and the above health issues, these concerns should be raised with the relevant supervisor, safety officer or health and safety representative. Assistance in measuring and controlling dust exposure can be obtained from Occupational Health and Safety. In addition, specific medical concerns can be discussed with the University's Consultant Occupational Physician.

For additional information, contact Occupational Health and Safety on: