Enclosure Classification
Class of a product that encloses a stronger laser, from the beam escaping through an opening and the window over it (IEC 60825-1:2014), and the optical density the opening needs for Class 1.
Educational only — not compliance-grade
These pages implement the published exposure limits for the cases each one states, but they are educational tools: no laser safety officer has signed them off.
- Do not use these results alone for PPE selection, NHZ / NOHD approval, controlled-area sign-off, enclosure/interlock approval, or formal classification.
- Always verify against ANSI Z136.1, IEC 60825-1, your local procedures, and the responsible laser safety officer / CLSO.
Accessible emission
500 µW
5.00 W through the opening, × 10^−4.00
Class of the product (IEC 60825-1:2014)
Class 1
Class 1 limit for this beam
1.92 mW
through binoculars (Condition 1)
OD the opening needs for Class 1
OD 3.41
met
OD for Class 3R
OD 2.72
A product that encloses a stronger laser is classified by what a person can reach outside it, the accessible emission (IEC 60825-1:2014). Here that is the beam escaping through one opening, attenuated by a window or filter over it; the product class follows from the class limits for that beam: for the naked eye a stop 100 mm away at 302.5 nm – 4 µm and at the opening elsewhere (7 mm at 400–1400 nm; the corneal stop in the infrared, 1 mm in the UV), and for binoculars a 50 mm stop at 2 m (modelled at 400–1400 nm), over a 100 s time base (30 000 s in the UV). A Class 1 product keeps the emission below the Class 1 limit in normal operation; panels that open onto the stronger beam need safety interlocks, or tools to remove them and warning labels (IEC 60825-1).
The opening passes the centred Gaussian beam's share 1 − exp(−2D²/d²). The escaping beam is classed as a Gaussian no wider than the opening, since all of its power lies within it: conservative near the opening, as a clipped beam diffracts more, which lowers the hazard only far from it. Not modelled: scattered and diffuse leakage, several openings, pulses, and whether the window or guard survives the beam (IEC 60825-4 tests laser guards).
Model and references
Textbook approximation. A standard approximation from the literature (for example paraxial, plane-wave or Gaussian-beam), valid within the range the page states. About the tiers
Accessible emission: the centred Gaussian's share through the opening × 10^−OD, in a beam no wider than the opening, classed with the IEC 60825-1:2014 CW AELs (classification page). Not modelled: scattered leakage, several openings, pulses, guard damage.
- IEC 60825-1:2014. Safety of laser products – Part 1: Equipment classification and requirements. Protective housing, accessible emission, Tables 3–8 (AELs). webstore.iec.ch
- ICNIRP (2013). Guidelines on limits of exposure to laser radiation of wavelengths between 180 nm and 1,000 µm. Health Phys. 105(3), 271–295. Tables 2–5 and 8. doi:10.1097/HP.0b013e3182983fd4
- IEC 60825-4:2006+A1:2008+A2:2011. Safety of laser products – Part 4: Laser guards.