Safety

Laser classes 1, 2 and 3R: what the standard says

Published on 21 septembre 2026 Updated on 28 septembre 2026 Reading time 6 minutes
A laser’s class describes the hazard it presents to the eye, under standard EN/IEC 60825-1. In class 2 the power stays at or below 1 mW in the visible, and the blink reflex is enough to protect the eye. Measuring instruments sold to the general public fall in practice under classes 1, 1M, 2 and 2M.

What does a laser class measure?

The class does not measure how good an instrument is: it describes the hazard its beam presents to the eye and the skin. It is set out in standard EN/IEC 60825-1, which brings together emitted power, wavelength and possible exposure time.

It must appear on the instrument, on its packaging and in its instructions. An instrument sold with no class stated is an instrument you know nothing about.

What do the classes mean, one by one?

Five classes apply to measuring instruments. Class 1 is safe in all foreseen conditions; class 1M except when the beam is viewed through an optical instrument. Class 2, visible and capped at 1 mW, relies on the blink reflex; 2M repeats class 2 with the same optical reservation. Class 3R is left to supervised professional use.

Class What the standard says Common use
1 Safe under all foreseen conditions of use Instruments with an enclosed beam
1M Safe except when viewing the beam with an optical instrument Widened beams
2 Visible, ≤ 1 mW; the blink reflex protects the eye Laser levels, distance meters
2M As class 2, except with an optical instrument Lasers with a widened line
3R Raised risk on direct exposure Supervised professional use

What is the blink reflex?

It is the involuntary movement that closes the eyelid against a bright light, in a fraction of a second. Class 2 rests on it: it takes the view that a brief, accidental exposure does not damage the eye. That reasoning no longer holds if you stare into the beam on purpose, or watch it through a magnifying optic.

What obligations come with the instrument?

The classification comes from standard EN/IEC 60825-1, which is the reference across Europe. Measuring instruments meant for the general public fall in practice under classes 1, 1M, 2 and 2M; class 3R is left to supervised professional use. The line between them is drawn by the standard, not by the seller.

As the importer, we carry responsibility for conformity: marking, instructions in the language of the country of sale, technical documentation kept available for the authorities. That is not a labelling formality, it is a responsibility.

What should you check before buying?

Four entries to look for before the price: the class written out in full on the instrument and in the manual; the wavelength in nanometres and the power in milliwatts; the manual in English, supplied with the instrument; and the reference to standard EN 60825 or to the declaration of conformity.

  • The class, written out in full on the instrument and in the instructions.
  • The wavelength in nanometres and the power in milliwatts.
  • The instructions in English, supplied with the instrument.
  • A reference to standard EN 60825 or to the declaration of conformity.

On our laser levels, this information is published for each model. Where a value is missing, the line does not appear and the conformity block says so.

What precautions day to day?

Never point the beam at anyone's face, do not stare into it, and do not view it through binoculars or a scope. Set the instrument at a height that keeps the line away from eye level in a walkway. And remember that viewing glasses raise the contrast: they are not safety glasses.

What to remember
  • The class describes a hazard, not a quality.
  • In class 2 the power stays below 1 mW and blinking protects the eye.
  • Instruments for the general public sit in classes 1, 1M, 2 and 2M.
  • The importer carries the manufacturer’s obligations.

Frequent questions

Can a class 2 laser damage your eyes?
An accidental, brief exposure is covered by the blink reflex. A prolonged direct exposure, or one viewed through an optical instrument, falls outside that. This is why you never stare into the beam and never look at it through binoculars, even in class 2.

Where do you find an instrument’s class?
On the instrument's label, on the packaging and in the manual. It must be readable without dismantling anything. An instrument sold with no class written on it is an instrument you know nothing about: check that before you even look at the price.

Do you need laser safety glasses?
Not for a class 1 or class 2 instrument used normally. The glasses sold for site lasers are visibility filters, not protection: they raise the contrast of the line. Real laser protection is chosen by wavelength and by a protection rating.