Exposure to wood dust has long been associated with a variety of adverse health effects, from dermatitis and asthma, to hypersensitivity pneumonitis and chronic bronchitis. It is estimated that carpenters and joiners are four times more likely to contract asthma than all other UK workers, according to HSE. Equally concerning is that certain species of hardwood, such as oak, mahogany, beech, walnut, birch, elm and ash, have been reported to cause nasal cancer in woodworkers – particularly where exposure levels are high.
This is endorsed by Dr Lesley Rushton, emeritus reader in occupational epidemiology in the department of epidemiology and biostatistics at Imperial College London, whose research points to occupational exposure to fine particulate wood dust as an established cause of such cancers – specifically nasopharyngeal and sinonasal. “Associations appear to be strongest for exposure to hardwood dust,” she states. Rushton, co-author of ‘Occupational cancer in Britain Nasopharynx and sinonasal cancers’ (www.is.gd/zojade), further comments: “The highest exposures have generally been reported for occupations in the furniture-making industry, although carpenters, machine operators, workers in the construction industry and in logging/forestry operations also experience exposure.”
In recognition of wood dust’s extremely hazardous impact on health, “causing serious non-reversible problems”, its danger was highlighted in last year’s publication of HSE’s EH40, Workplace Exposure Limits document (fourth edition), requiring that employers protect workers from wood dust. Both hardwood and softwood dusts have a Workplace Exposure Limit (WEL) that must not be exceeded. The WEL for hardwood dust is 3mg/m3 (based on an eight-hour time-weighted average). For mixtures of hardwood and softwood dusts, the WEL for hardwood dust of 3mg/m3 applies to all wood dusts present in that mixture, even though the WEL for softwood dust is slightly less, at 5mg/m3.
Dust is generated by the machining and working of wood and wood-containing materials, such as chipboard and fibreboard. Operations such as sawing, turning and routing produce relatively coarse dust while sanding and assembly operations generate fine dust. What is essential for employers in those industries and environments where hardwood is involved is for adequate control of wood dust.
The regulations cited above, which set out the legal requirements to protect workers from health risks arising from hazardous substances at work, state that employers (including contractors) have a duty to carry out a suitable and sufficient risk assessment – and take steps to ensure they prevent or adequately control exposure.
In a move that should be sending out a stark warning to industry, HSE inspectors across the UK are now targeting construction firms to see how they deal with dust hazards on site. “Inspections will focus on respiratory risks and occupational lung disease, looking at the measures that businesses have in place to protect their workers’ lungs from the likes of silica, wood dust other harmful dusts, such as asbestos,” says Chris Power, training manager for health and safety consultancy at Socotec UK, a provider of testing, inspection and compliance services in the UK. “These visits will be unannounced, with inspectors able to attend your site at any reasonable time. If the site is found not to meet the required assessment criteria, the results can be enforcement notices or even prosecution,” he adds.
Employers should keep these many health risks in mind, advises Socotec UK’s occupational hygiene team leader Mary Cameron, when deciding which materials to purchase, aiming to avoid wood altogether or purchase lower-risk wood materials where reasonably practicable to do so.
“The effects of handling higher-risk wood materials not only have an impact on the potential health outcomes of the worker, but will require the implementation of a higher level of control measures, as well as a higher level of health surveillance,” she points out. “These subsequent costs can add up, which purchasing lower-risk wood materials from the get-go could have avoided.” Management of dust hazards – including wood dusts – might include dust monitoring, equipment hire and nuisance dust assessments to ensuring compliance through COSHH Awareness training, she adds.
Those who engage actively with the HSE usually have good practices already in place, such as fixed extract provision with carefully-planned servicing, says Nathanael Challacombe, group HSQE manager at construction company Barnwood. “Fixed LEV extract systems and fully-enclosed machinery are available, but these are often perceived as expensive in a market where there is plenty of second-hand machines without containment available. Those who use portable-extract equipment, rather than the more robust, but expensive, fixed-extract equipment, tend to service and maintain their equipment less frequently. That said, you don’t necessarily need the latest commercial solutions, as appropriate equipment has been around for some time.”
Using simpler methods, such as a type-M vacuum to hoover up dust on floors and surfaces, rather than using a brush, will not only clean the workshop quicker, but, if used regularly throughout the day, help reduce the wood dust exposure dramatically, adds Challacombe, who is on the committee of the IOSH Construction Group and also a HSE Wood Safety Group committee member. “But extract methods must be used with RPE [respiratory protective equipment] to provide the best protection.”
One concern he highlights is that many smaller companies feel they cannot go to the HSE for advice in the way they used to do, as they fear an inspection and possible ‘fee for intervention’ (FFI) fine. “The HSE and industry are aware there are limited resources to help improve controls in smaller companies, but the HSE themselves, through FFI, have created a perceived culture of fear, which needs to be reversed.”
Ultimately, promoting good control practice and challenging existing work attitudes to improve hard wood dust control will, he believes, be a joint effort between employers and the HSE. “Schemes like the Working Well Together [www.is.gd/otusoc], IOSH’s ‘No Time To Lose’ campaign [www.is.gd/zenufe] and the BOHS ‘Breathe Freely’ campaign [www.is.gd/bulequ], along with the involvement of the HSE Wood Safety Group, all promote awareness and will help employers to put the correct control measures in place that protect employees’ long-term health.”
FIRES AND EXPLOSIONS
Health issues aside, there are other considerations that need to be taken into account, such as the inflammability of wood dust, which, in certain situations, can cause a fire or explosion. “Every year, premises are severely damaged or destroyed by wood dust fires that usually start in dust extraction equipment,” the HSE points out. A video on the WorkSafeBC website graphically illustrates why these particles are such a hazard in sawmills and wood shops, and how the risk of fires and explosions are greatly increased, potentially causing catastrophic injuries, loss of life and destruction of buildings: see www.is.gd/omiwic.
Fortunately, these events are preventable, and dust extraction, which forms an essential role in keeping employees safe from the dangers that hardwood dust poses, should always be employed at woodworking machines to capture and remove dust before it can spread.
There are many suppliers who offer a wide range of equipment to ensure wood dust extraction is carried out in compliance with healthy and safety requirements; they include Arco, Ashtead Technology, Dustcheck and Dustcontrol. Making contact is an important first step in deciding how best to protect your workforce and the business.