Industries
Explosion protection in the wood and metal industry
Both woodworking and metalworking produce combustible dust, but the two hazards are not the same. Wood dust is organic and non-conductive. Metal dust, aluminium and magnesium in particular, is conductive and reactive. It even reacts with water. The classic and dangerous mistake is to treat the two dusts as one, or to route them into a shared extraction system. The documentation has to keep the dust types, the zones, the extraction systems and the protective measures current. That is where EPDS helps.
Industry experience
Sound familiar?
Both wood and metal are machined, but the wood dust and the metal dust go into the same extraction system.
Aluminium is being sanded, and it is not clear whether the classification accounts for metal dust being conductive and reactive.
A wet dust collector is connected to metal dust too, even though the reaction between aluminium and water can generate hydrogen.
A new CNC machine or sander is installed, but the zone classification does not follow the change.
Ahead of an audit you spend days gathering the zone drawings, the equipment list and the inspection certificates.
If any of this sounds familiar, what you need is not another document but software that lives alongside the dust types and the extraction systems.
Hazards
Typical explosion hazards in the wood and metal industry
The industry deals with dust hazards, but wood dust and metal dust behave fundamentally differently:
| Hazard source | Where typical | Typical zone |
|---|---|---|
| Wood dust (organic, IIIB) | sawing, sanding, milling, extraction systems, silos | dust zone (20/21/22) |
| Metal dust: aluminium, magnesium (conductive, reactive) | sanding, polishing, cutting, deburring, CNC | dust zone (20/21/22), IIIC |
| Mixed dust (wood and metal together) | shared extraction, shared dust collector | dust zone, heightened hazard |
| Settled dust | surfaces, beams, the tops of machines | dust zone (22), secondary explosion |
| Mechanical sparks and hot surfaces | sanding, cutting, bearings | an ignition source in every zone |
Wood dust falls under the usual dust protection, but alongside the explosion risk it also carries a fire risk from smouldering. Metal dust is another order of magnitude: its minimum ignition energy is lower, its explosion is more violent, and because it conducts, equipment selection is stricter too. The highest-risk points are the sanders, the polishers and their extraction systems. As CNC machining and metal 3D printing spread, reactive metal dusts are appearing in more and more plants.
When we help
Typical situations when it’s worth talking
Wood dust and metal dust: two different hazards, not one
The most common and most dangerous error is a plant treating metal dust the same way as wood dust. The two differ on four points:
Wood dust is organic and non-conductive. It falls into dust group IIIB; the usual dust protection applies, but smouldering also presents a fire risk.
Metal dust is conductive and reactive. Aluminium and magnesium fall into dust group IIIC; because the dust conducts, equipment selection is stricter.
Metal dust reacts with water. A wet dust collector is dangerous with metal dust, because aluminium and magnesium can generate hydrogen with water. Metal dust needs a dry solution designed for it.
Do not treat the two as one. Do not route wood and metal into shared extraction; mixed dust is more dangerous than either on its own.
The solution
How EPDS helps in the wood and metal industry
EPDS brings explosion protection documentation into one system, from the dust types through to the extraction systems:
Dust, zone and equipment register in one place.
EPDS holds the type of each dust (organic or metal), its dust group and Kst data, the zones and every Ex device in one place.
Tracking the separation of extraction systems.
The software records which extraction system belongs to which dust, so wood and metal do not mix.
Management of change.
The software traces the effect of a new machine (CNC, sander, polisher) through the zones and the protective measures.
No more overdue inspections.
The system gives notice of inspections as they fall due, and records the ones completed.
An audit-ready report in one click.
EPDS assembles the report of zones, equipment and inspections, per site too.
Documentation that is always current.
You can look back at any time to see who changed what, and when.
Knowledge hub
Before you decide, get informed.
Our expert knowledge base explains the concepts of explosion protection clearly.
FAQ
Frequently asked questions
Why is metal dust more dangerous than wood dust?
Metal dust, aluminium and magnesium in particular, is conductive and reactive. It ignites at lower energy, explodes more violently, and can generate hydrogen with water. It therefore falls into dust group IIIC and calls for stricter equipment selection and protection than organic wood dust.
What is the problem with wood and metal sharing one extraction system?
Mixed dust combines the two hazards and is more dangerous than either on its own. Wood and metal therefore have to be routed into separate extraction systems.
Can I use a wet dust collector for metal dust?
With aluminium and magnesium this is risky, because the metal can react with water to generate hydrogen. For metal dust you have to choose a dry solution designed for the purpose.
When does the zone classification have to be redone?
At every change that affects the explosion hazard: a new machine, a different raw material, or a modification to the extraction or the process. In EPDS this is part of management of change.
Does a joinery or metalworking shop need explosion protection documentation?
Yes. Wherever combustible dust can create an explosive atmosphere, the documentation is mandatory under decree 3/2003. (III. 11.), and it has to be kept current.
Let’s talk it through — free consultation
In a short, free conversation we show you the EPDS system mapped onto your processes, and review where your documentation stands today.