Laser engraver safety basics
Essential precautions for fire prevention, eye protection, and fume management when operating desktop lasers.
Lasers can start fires within seconds and can permanently damage your eyes. The GRBL laser-mode documentation opens with that warning.
Stay with the machine while it runs, keep a suitable fire extinguisher nearby, and use the eye protection rated for your laser's wavelength (your manufacturer's manual states it).
Ventilate and filter the fumes. Some materials release dangerous gases or dust. Trotec lists, for example, PVC, PVB, PTFE (Teflon), carbon fibres, beryllium oxide, leather tanned with chromium (VI), and materials containing halogens, epoxy or phenolic resins as unsuitable for laser processing.
Check speed units before you run anything: LightBurn warns that mixing mm/s and mm/min can cause excessive power and fire risk.
Always frame a job before running it, and start test cards with the weakest settings.
Sources
- GRBL v1.1 Laser Mode (GRBL wiki)
$32=1, M3 vs M4, G0 never fires laser, safety warning
- LightBurn — Material Test
run order "highest speed, lowest power first"; unit warning
- Trotec — Unsuitable laser cutting & engraving materials
materials list for safety page
Last reviewed: 2026-10-26