Are laser cutters a fire hazard?

Question

Accepted Answer

Yes. A laser cutter works by burning material away with concentrated heat, so a flare-up is always possible, even in a well-kept machine.

Yes. A laser cutter works by burning material away with concentrated heat, so a flare-up is always possible, even in a well-kept machine. That is why an authorized person stays with every job and why any flame means stop. What lowers the odds of a laser cutter fire, and the one control nothing replaces A band across the top, marked with an eye, says nothing replaces a person watching the cut: you need to see the cut clearly to catch a flare-up, and cameras and alerts don’t stand in for a person. Below, a grid of four things that lower the odds: a tray cleaned of debris, because debris is fuel; working exhaust, because weak exhaust may make a fire more likely; air assist checked before each run, because it removes heat and debris at the cut; and not placing the machine on a combustible surface such as wood. A caution line says a flare-up is always possible, even in a well-kept machine. A band at the bottom says any flame means stop: stop the machine with the emergency stop or the switch you were trained to use; don’t open the lid to look; move students away; follow your written fire procedure; and if it becomes a fire, get everyone out and never go back in. Nothing replaces a person watching the cut You need to see the cut clearly to catch a flare-up. Cameras and alerts don’t stand in for a person. What lowers the odds Tray cleaned of debris debris is fuel Working exhaust weak exhaust may make a fire more likely Air assist checked before each run it removes heat and debris at the cut Not on a combustible surface such as wood A flare-up is always possible, even in a well-kept machine. Any flame means stop Stop the machine with the emergency stop or the switch you were trained to use. Don’t open the lid to look. Move students away. Follow your written fire procedure. If it becomes a fire, get everyone out and never go back in. The four checks lower the odds; the person watching catches the flare-up that happens anyway. No rate is shown because we could not find a published one. Your written fire procedure sets the details. This answer covers an enclosed, interlocked machine that is Class 1 or Class 2 in the configuration you run. An open-frame, open-bed, pass-through or converted machine, or one that is Class 3B or 4 in normal use, is not covered here. It needs a laser safety officer and a written program first, and if no one can be designated, the answer is not yet. MIT says even a properly maintained and exhausted laser cutter may occasionally have flare-ups that, unobserved, can grow into a larger fire. Carnegie Mellon says the heat can lead to a fire inside the cutter and names cardboard as prone to it, and MIT says foam core has been involved in fires at MIT and other locations. We could not find a published rate for laser-cutter fires: the old national fire reporting system had no laser-cutter category and the new one files them under shop tools, so we won’t give you a number. The usual contributors are ordinary ones (see why laser cutters start fires). Debris is fuel: UW–Madison says dirt and debris may cause fire and to clean the tray when residue builds up. MIT says insufficient exhaust removes heat and debris less efficiently and lets the optics get dirty faster, which may make a fire more likely. Air assist removes heat and debris at the cut and can help prevent flare-ups, so check it works before each run. And MIT says not to place the machine on wood or another combustible surface. Watching is a control nothing else replaces; cameras and alerts don’t stand in for a person. MIT says you need to be able to see the cut clearly to catch a flare-up. If a flame appears, stop the machine with the emergency stop or the switch you were trained to use, don’t open the lid to look, move students away, and follow your written fire procedure. If it becomes a fire, get everyone out and never go back in.

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