Most common hazardous substances found in the workplace have established exposure limits set by the HSE. In today’s blog, we’ll look at what wood dust exposure limits are and how a proper extraction system will keep your employees below them – keeping your business legally compliant.
There are many substances that are hazardous to health. How hazardous they are depends on their type, form, and the route of exposure.
Paints for example may be water, oil or solvent based. Employees may be exposed to them in liquid, vapour, droplet or even dust form. It may come into contact through skin exposure, breathing in the dust/droplets, through the eyes, or even through ingestion.
The impact on the employees’ health will vary depending on all these factors.
So how do employers know just how harmful a substance is?
This is, after all, crucial information that is required in order to properly and reasonably control the substance. (Imagine not knowing how harmful asbestos was, assuming it was relatively benign, and stating in your risk assessment that simply opening a window and washing hands were adequate controls).
Luckily, the HSE has well established quantitative exposure limit values for a variety of substances that are harmful to health, that can be found in the majority of workplaces.
These are expressed as the amount of the substance (in milligrams) per m3 (cubic metre) of respirable air within the workplace and are weighted against either a fifteen-minute exposure duration, (Short Term Exposure Limit- STEL) or eight-hour duration (Long Term Exposure Limit- LTEL).
The wood dust exposure limit values are available for both STEL and LTEL.
In case you hadn’t noted, this does indeed mean that the WELs only provide exposure limits for respirable substances, and therefore account for exposure through breathing.
The exposure limits associated with wood dust are thankfully well established and documented.
The wood dust exposure limits vary depending on the type of wood. It’s important to be sure of the type of wood you’re working with. If it’s a mixture of types, make your judgement based on the most harmful type.
So, what are the Wood Dust Exposure Limit values, set by the HSE? They are:
Therefore, for mixtures of hardwood and softwood, the wood dust exposure limit is 3mg/m3.
It’s important to note that finer dust particles are more harmful than coarser dusts. So, if you’re carrying out abrasive finishing rather than rough sawing, it is even more important that you control your employee exposure to wood dust.
To understand what your existing employee exposure levels are, you’ll need to carry out a workplace dust survey. This is usually in conjunction with a third-party monitoring service, (as they are “competent” by law).
They will place dosimeters onto employees and around the workplace to benchmark typical dust levels, and therefore gauge whether your employees are reaching the Exposure Limit Values (ELV).
It’s likely that they will be able to offer noise and vibration benchmarking too, which you are also required to assess by law.
Exposure to wood dust can cause a variety of health issues. These can be both short term (acute) or long term (chronic).
Short term effects include shortness of breath, irritation of eyes, nose and throat, and rhinitis. Long term effects can include occupational asthma, and in the case of hardwood dust, cancer of the respiratory system.
Little wonder therefore that the HSE has such well-established wood dust exposure limits.
Exposure to wood dust can be difficult to control, depending on the equipment in use. Older equipment may not have spigots or duct ports to allow extraction at source, and minimal guarding to boot. If poorly maintained, it’s possible that there will be holes and gaps in the equipment casing that allow dust to escape.
Furthermore, in larger-scale industrial environments such as sawmills, and particularly on older installations, it’s quite likely that there will be by-product (a.k.a waste or co-product) handling systems such as conveyors, augers, screens, ducts and cyclones, which can all release wood dust through cracks, holes, joints, and transitions (for example from one conveyor roller onto another, where a change of direction is required) as it is transported.
So, how do you control this hazard and keep your employees below the safe wood dust exposure limits?
There are actually a few different approaches:
While reducing the amount of dust created in the first place seems like a sensible place to start, it’s not always the most practical or even feasible. If wood needs to be processed, dust will be created – it’s unavoidable.
Therefore, the most effective means of remaining below the wood dust exposure limits is through capturing the dust at source, with a dedicated extraction system.
A wood dust extraction system is the most effective way of staying below the wood dust exposure limits, while maintaining operational efficiency and productivity.
They offer a means of protecting everyone in the vicinity (a collective control) rather than simply protecting a single employee (i.e. with RPE).
What’s more, because you’re avoiding the use of RPE, your employees won’t feel hindered by having to wear uncomfortable equipment (which in most cases is ineffective anyway, due to employees’ facial hair) meaning they can focus on the task in hand, maintaining productivity and upholding quality standards.
Controlling wood dust at source also means that the entire workplace is more clean, equipment will last longer, (dust isn’t working its’ way into bearings etc, or sappy, resinous dust isn’t sitting on equipment surfaces, for example), the ground is safer to walk on (so reduced likelihood of slips, trips and falls) and you’ll have to take less time out of production to carry out housekeeping.
Can you see why capturing the wood dust at source is the best option now?
At Fumex, we specialise in designing, creating and installing bespoke and off-the-shelf dust extraction systems.
Depending on your workplace size, operational activities and the types of wood dust, we’ll specify a system that is optimised for you. Whether that’s a smaller, portable system for simple equipment, or a large-scale fixed solution that can handle multiple machine centres creating dust simultaneously.
Our systems come with powerful fan motors and industry leading filtration so you can count on the most efficient dust extraction possible, and the cleanest air released.
While they’re simple and low maintenance, we offer an after-sale maintenance service. This ensures that your extraction system is always in top condition, and any repairs, as unlikely as they are, can be dealt with swiftly.
So, to stay below the wood dust exposure limits, protect your workforce, make your workplace safer…and stay compliant with the HSE…give our in-house extraction experts a call today.
