With the high risk of fire and explosion being an obvious hazard in the woodworking industry, it is not easy to keep up with both the latest legislation and increasing HSE and insurance checks on proper dust extraction equipment. Modesta often receives questions on ATEX or EN standards – but what do these regulations mean, and why are they necessary?
Imagine it is the end of the working day in your factory, and everyone is about to head home. While the last door is being sawn, a hot particle is sucked into the dust extractor and reaches the filter installation, where it starts to smoulder. By now, all the staff have actually gone home, and a fire could spread quickly without anyone noticing.
The fire originated in the wood storage of this particular doors and windows company. In this case, the safety equipment worked to preserve the filter
s harrowing as the idea of your filter installation burning down overnight might be, it would be even worse if the fire spread to the factory itself. There are so many aspects of the production process involving fire and explosion hazards, and just as many measures one can take to minimise these risks as far as possible.
But it is just as important to have the right fire-regulating measures in case a fire or explosion does actually occur. This is what happens several times a year in woodworking factories across the country – a filter that complies with legislation prevents flames or an explosion from spreading to the rest of the factory.
Minimising fire and explosion hazards is vitally important in a working environment where all the elements needed for a fire to ignite or an explosion to occur are naturally present – heat, an inflammable substance (such as sawdust), and oxygen.
A factory also has to comply with European and local legislation. Wyboud Kloppenburg, MD of Modesta Filters, says: “We understand that keeping up with all these different regulations is complicated, and it’s not the first priority of a woodworking professional. That’s why we would like to offer our expertise and years of experience in dust extraction to provide a clear overview of the rules, potential hazards and possible solutions.”
To understand legislation like the DSEAR, one must first take a look at European regulations. All machinery used in the EU needs to bear the CE mark, which testifies that the machine has been designed in accordance with any equipment-relevant safety guidelines. ATEX, the name used for European directives covering explosive atmospheres, comes into play in industries where combustible dusts or fuels are used or produced during production.
To make ATEX easier, several institutes have designed harmonised EN standards that offer the machine designer and user a more practical way of dealing with the legislation. A few of these EN standards apply in the wood and interior industry: EN 12779 for the safety of woodworking equipment and dust extraction; and EN 16770, which specifically covers extraction units for indoor use.
Note that ATEX focuses mainly on the safety of personnel, limiting the damage and containing the fire or explosion when it happens, but it does not necessarily consider the prevention of fire and explosion hazards. Units designed in accordance with EN 12779 are the way to go if one wants to make sure that the system complies, states Modesta.
In Great Britain, the requirements specified in ATEX were put into effect through the Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR).
“In a woodworking factory, every part of the production process comes with its own specific fire and explosion hazards,’ says Wyboud. “It’s important to be able to identify these and come up with a fitting solution.”
The QEX quality mark guarantees the installation complies with all legislation and (local) requirements
For starters, a woodworking machine can be a fire hazard in itself if dull tools are used, or if its parts are jammed or not running smoothly, resulting in sparks. That is why regular and thorough maintenance is vitally important when minimising fire and explosion hazards. Even when machines are properly maintained, sparks can also occur due to small metal pieces and hot particles being sucked into the extraction system.
Sawdust from wood production is extracted into a ducting system before ending up in the filter itself. The sparks can set leftover sawdust on fire in the ducting system. Wyboud says: “This can be prevented by always ensuring that your filter system has a sufficient extraction capacity for the size of the factory you’re operating, to prevent dust accumulation in the ducting.”
Factory plans and production capacity can change over the years, resulting in a different set-up or a higher extraction need. “When the system isn’t operating within its ideal range, this doesn’t just mean a loss of energy, but it’s also a potential fire hazard,” explains Wyboud – which is why it is so important to reassess the capacity of the dust extraction system regularly, especially when changes occur on the factory floor.
A periodic Local Exhaust Ventilation (LEV) test is mandatory and essential in maintaining a safe working environment. But this test assesses the extraction capacity of a system, not the risk of sparks within it. Although not mandatory according to ATEX regulations, a spark detection system, combined with an automatic fire-extinguishing system, will prevent fires in the pipes.
The filter system itself can also pose a danger, as any ignited sparks in the ducting system will be sucked into the filter itself. Fire valves offer the solution here, states Modesta – they make sure the fire is contained in the filter, and prevent further damage to the rest of the factory.
“Fire hazard should be considered at the very beginning of setting up a factory,” says Wyboud. For instance, the positioning of the filter system itself can prevent major damage if a fire or explosion occurs – installations over 8000m3/h should be positioned outside the factory walls and have the right fire-extinguishing connections for the fire brigade.
According to ATEX regulations, the explosion’s pressure wave has to be able to leave the installation safely. To guarantee this, explosion panels must be installed in the filter itself, and in the return air ducts going back into the building.
Positioning storage spaces for wood and sawdust is also important – they should be as far away as possible from the filter installation and factory buildings (preferably in a separate building) to minimise the risk of a transient fire. Filter systems with a capacity up to 8000m3/h can be installed inside the factory, but among other things, they should have their own extinguishing system, according to EN 16770. Units for indoor use need to be able to withstand an explosion.
Fire and explosion safety is not just about preventing risks within a specific system. Wyboud says: “We would like to raise awareness in every aspect of the factory, as we believe the factory’s safety is more than the sum of its parts.”
From woodworking machine positioning to a ducting system, absolutely everything should be considered when setting up a safe and hazard-free factory floor. Modesta can help manufacturers in taking both fire-prevention and fire-regulation measures, considering their entire set-up critically, and advising the steps to take towards a safer working environment. Lastly, Modesta applies the QEX Quality Mark certification, which simply means the installations meet all legislation and (local) requirements.
