Wood dust monitoring and health surveillance: Best practice for builders merchants

Workplace exposure limits (WELs): The basics

In the UK, workplace exposure limits for wood dust are set by the Health and Safety Executive. They outline the maximum concentration of a hazardous airborne substance that most people can be exposed to without suffering health issues. This includes exposure to harmful particles created by:

• Cutting or sawing
• Sanding
• Routing
• Changing dust bags
• Dry sweeping

Under the Control of Substances Hazardous to Health 2002 (COSHH) Regulations, it's your duty to safeguard staff from exposure to hazardous substances so far as reasonably practicable.

It's important to note that not all WELs are the same. This is because hardwoods, like oak and beech, have a higher potential to cause cancer. Softwoods, such as pine, have a lower potential to cause cancer. By knowing the WELs, we can understand if our control measures (e.g. ventilation) are working:

• Hardwood: 3mg/m3
• Softwood: 5mg/m3

According to COSHH rules, if wood dusts are mixed together, you must not exceed the lower WEL.

Assess the risk in your builders merchant

To protect your team, begin with a thorough risk assessment to identify sources of wood dust and evaluate their exposure hazards. An effective risk assessment should:

• Measure the concentration of dust in the air across different locations in your branch and during various tasks and processes, such as sawing or sweeping.
• Compare the measured concentrations to the HSE's published WELs for each material.
• Consider how long and how often your workers are exposed.

Adopt a 'belt and braces' approach

Armed with a clear picture of exposure risks in your branches, you can assess and improve your current safety controls. Aim to tackle hazards from all angles, including comprehensive staff training, adequate ventilation, and suitable personal protective equipment (PPE):

• Train workers to recognise and report the early signs of wood dust exposure. These include coughing, wheezing, shortness of breath, headaches, allergic reactions, and eye, throat, and skin irritation.
• Ban dry sweeping within a mill or machining area.
• Use a high-powered dust lamp to pinpoint particularly hazardous areas.
• Change dust bags when they reach two-thirds full to prevent spills and excess dust.
• Install local exhaust ventilation (LEV). This is widely accepted as your strongest defence against airborne particulate dusts.
• Keep your LEV system in peak condition. After installation by a qualified professional, your system should be thoroughly examined every 14 months.
• Provide HEPA filter or M Class vacuums to remove excess wood dust in areas that LEV extensions can't reach.
• Wear appropriate PPE, such as FFP3 masks and gloves, when changing dust bags.
• Use respiratory protective equipment (RPE) in addition to LEV when sanding.
• Provide face fit testing as part of your risk assessment when FFP3 masks are required.

Step up safety with ongoing health surveillance

Routine health surveillance helps you take a systematic approach to worker wellbeing. The use of questionnaires can help you to establish a 'baseline' for new and existing employees.

Spirometry

Spirometry is a lung function test used to diagnose and monitor respiratory conditions, such as asthma, chronic obstructive pulmonary disease (COPD), and other lung conditions.

• Spirometry helps you track declining lung function over time, detecting wood dust-related health issues before they become severe.
• It also provides a before-and-after assessment of your protective measures.
• Baseline testing establishes existing lung function levels across your workforce.
• Afterwards, periodic testing monitors changes and highlights possible health concerns.
• Ad hoc spirometry testing should be carried out following a known increase in wood dust exposure.

Air monitoring

Air monitoring uses air samplers and dust monitors to measure the concentration of wood dust particles in your workplace. It helps you remain within safe limits, identify risk areas, and assess how well your safety controls work.

• Your initial assessment should identify baseline wood dust levels in various zones of your site. Following that, regular monitoring on a monthly or quarterly basis will track fluctuations over time.
• Enhance your monitoring programme when using new processes or equipment.
• Regularly analyse monitoring results to pinpoint risks, red flags, and improvement areas.
• Real-time monitoring is also available, providing ongoing measurement of exposure risks.

Other surveillance duties

Wood dust is rarely the only health risk in a machining area. The saws, sanders and routers that generate dust also transmit hand-arm vibration, which carries its own surveillance duty under the Control of Vibration at Work Regulations 2005. If the same workers run those tools for much of the day, our free HAVS exposure calculator shows whether daily exposure reaches the action or limit values.