Laser hazards

There are more than 200 lasers at EPFL. Most of them can cause eye and skin injuries to anyone who is exposed to the direct beam or its reflections. The type of damage and the threshold at which each type of lesion is produced depend on the laser beam parameters (power, wavelength, divergence of the beam), the exposure time and the absorption properties of the material exposed to laser light.

All users of lasers with open beam have to follow classroom laser safety training or the online laser safety training. If you have any problems accessing the online training, please contact us.

In case of an incident

1. Switch-off the laser system

2. Call the emergency number 115 or +41 21 693 30 00

3. Rescue staff: first aid, evacuation, etc.

4. Inform the head of the laboratory as soon as possible

5. Do not resume use of the laser system until the accident has been reviewed.

6. If a laser eye injury is suspected, the injured person must keep their head upright and still to restrict any bleeding in the eye. Laser eye injuries should be evaluated by a physician as soon as possible.

Internal directive Control of laser risks applies to all lasers belonging to class 3B and 4 that emit radiation in the wavelength range from 180 nm to 1 mm at the EPFL.

Lasers are classified into 8 classes (1, 1C, 1M, 2, 2M, 3B, 3R, 4). Laser hazardousness increases as the class number increases.

Commercial lasers are classified by the manufacturer. If you and your colleagues modify a commercial laser or build a new one in your lab, the main researcher in the group is responsible for the classification of the laser. You can contact us to get help in this task.

Class 1
Class 2
Considered harmless if the exposure duration is less than 0.25 seconds (the average human blinking time).
Class 3
Hazardous to eyes and skin. Specular reflection is hazardous.
Class 4
Extremely hazardous to eyes and skin. Reflected and diffuse light are hazardous. It ignites flammable material.

Be extremely careful with pulsed lasers: they often belong to class 4.

  • Access to the laser hazard zone is granted after passing the Laser training.

  • Laser training consists of a laser equipment specific training and either classroom laser safety training or an online laser safety training with test (see chart below).

  • The lab head must organize laser equipment specific training and have a written evidence of past trainings.

  • Classroom laser safety training is similar to the online one but is more comprehensive. If a classroom laser safety training is soon available, privilege it.

Wavelength Effects on the eyes Effects on the skin
180 – 280 nm Photokeratitis 1st degree burn (e.g. sunburn)

Accelerated skin aging

Pigment darkening

280 – 315 nm
315 – 400 nm Cataract related to photochemical process Pigment darkening

Skin burns

Photosensitive reactions

400 – 780 nm Retinal injuries, photochemical and thermal
780 – 1400 nm Cataract

Retinal burns

Skin burns
1400 – 3000 nm Burns of the cornea

Protein level increase in the cells of the aqueous humor

IR cataract

3000 – 106 nm Burns of cornea

There is no need for laser registration in Switzerland.

Nevertheless, OHS demands a registration of the new lasers/ laser setups.

To register please contact us by opening a request for support on laser safety. The link is available on OHS main page. OHS laser safety officer will come to verify that all the requirements of the internal directive on controlling laser risks are met.

You can check what measures you will need to comply with according to the EPFL internal directive: Control of laser risks.

Experimental area delimitation

  • The area where a laser is used is delimited and the access restricted (CAMIPRO, key)

  • The lab door must close automatically. If the key is used to control the access, the door must be equipped with a knob handle on the outside.

  • To avoid visitor’s exposure to the beams, laser proof curtains must be installed at the lab entrance and must be kept closed when the laser is on.

  • A signalisation lamp showing that the laser is on must be placed above the door outside the laboratory. The bulb must be a white diode and the light must blink.

  • A doorbell must be installed at the entrance of the laboratory. When the laser is on, visitors must ring the bell and wait for permission before entering the laboratory.

Confinement on the optical table

  • The beam paths are enclosed when possible.

  • The optical bench is free of unnecessary reflective items.

  • The laser beam must be confined in a plane lower than the eyes of a seated or standing person.

  • The personnel sitting at the work stations (computers) have to be protected against beam exposure.

  • Jewellery, watches and reflective tools are forbidden.
Experimental area delimitations in the order of preference (most preferred on the left side)
© Laser Safety, R. Handerson and K. Schulmeister, IOP, 2003

Personal protective equipment (PPE)

  • The laser protective eyewear (undamaged) has to be worn by all personnel working with lasers

  • The research group is in charge of purchasing the laser protective eyewear. it is specific to the lasers used and certified EN207. Either the vendor or the OHS can help you choose the correct goggles.

  • If no ocular protection is available for a particular setup, only the personnel duly trained for this situation are authorized to enter the laboratory. The written orders are given to everyone by the laboratory head.

The EPFL takes charge of a part of the entire price of medical laser eyewear.

This part includes the price of “standard” glasses and the eye exam. The bill is paid entirely by the OHS and an internal invoice for the difference is later sent to the group. The form to get the medical laser eye wear is available on this page.