Industrial Safety: Laser Enclosures and Interlocks

Class 4 Laser Safety

Class 4 lasers cause permanent eye and skin damage instantly — even reflected beams. A proper enclosure is non-negotiable for any open-frame diode or CO2 laser.

Enclosure Requirements

Use enclosures rated OD6+ for your laser's wavelength. Diode lasers (450nm) require OD6+ at 450nm. CO2 lasers (10.6μm) require panels that block infrared. Check the OD rating on every panel, not just the door.

Interlocks

Magnetic safety interlocks kill power the moment a lid opens. Wire them in series — any single door opening cuts power. Use normally-closed (NC) switches so a broken wire means laser off, not laser on.

For PLC setups wire interlock circuits through a dedicated safety relay, not a digital input. Safety relays detect welded contacts and fail-safe. Map the signal to an E-stop input — never use it as a soft stop only.

Ventilation

Minimum 100 CFM exhausted outdoors through HEPA + activated carbon filtration. Some materials (PVC, ABS, polycarbonate) produce genuinely toxic gases — never run these without verified exhaust. A smoke detector inside the enclosure wired to the E-stop is cheap insurance.

PPE

Wear OD7+ laser safety glasses rated for your exact wavelength any time the enclosure is open with power possible. Standard safety glasses are useless.

Fire Safety

Never leave a running laser unattended. Keep a CO2 extinguisher within arm's reach. Check your bed after every session for smoldering material.