Know the material before you cut it
The most important laser setting isn’t on the machine — it’s knowing what the material is. Some common materials release toxic gas or catch fire under a laser, and the label doesn’t always tell you.
Applies to
- Process
- CO₂, diode & fiber lasers
- Materials
- Anything you didn’t make yourself or can’t identify
- Worst offenders
- PVC / vinyl (releases chlorine gas), unknown plastics, coated stock
Why it matters
PVC and other chlorine-containing plastics release hydrogen chloride gas when lasered — it’s toxic to you and corrodes the machine. Other materials flare up or off-gas fumes you don’t want to breathe.
The Safety Data Sheet tells you what a material is made of and what it releases when heated. If you can’t identify a material or find its SDS, treat it as unsafe and don’t cut it.
What good looks like
- Every material is positively identified before it goes on the bed
- You’ve read the SDS and confirmed it’s laser-safe (no chlorine/PVC, no toxic off-gassing)
- Exhaust and fume extraction are running for every job
How to apply it
- Identify the material — supplier spec, a PVC/chlorine test, or don’t cut it.
- Pull up the SDS and check hazards, decomposition products, and flammability.
- Reject PVC/vinyl and anything you can’t verify as laser-safe.
- Run exhaust/extraction and stay with the machine while it cuts.
Common mistakes
- Cutting mystery plastic to ‘see what happens’Identify it first; unknown = don’t cut
- Assuming ‘vinyl’ is fineVinyl/PVC releases chlorine gas — never laser it
Which materials are dangerous to laser and how to read an SDS — DANGEROUS LASER ENGRAVING MATERIALS | FIND AND USE SDS FOR LASER SAFETY ↗.
Summarized and independently edited by Start Here. Starting values and cautions are our editorial notes, not a quotation from the creator.