Summary of requirements for particular classes of laser devices (based on PN-EN 60825-1:2010 standard)

Class	1	1M	2	2M	3R	3B	4
Description	safe under foreseeable conditions	safe to the naked eye; can be dangerous if used with optical equipment	safe in the case of a short look into the beam; aversive reflex ensures protection	safe in the case of a short look into the beam; can be dangerous if used with optical equipment	potentially hazardous when looking directly into the beam	hazardous when looking directly into the beam; the reflected beam can be dangerous to the eyes	dangerous to the eye and the skin when exposed to the direct beam and the reflected beam (even when dispersed) risk of fire
Protective housing	Required for all laser devices. Limits access necessary to ensure the functioning of the device
Security lock in protective housing	Designed to prevent removal of the plate, until the values of the available emission are below the limits for 3R class				Designed to prevent removal of the plate, until the values of the available emission are below the limits for 3B class or 3R class for certain devices
Remote lock switch	Not required					Allows easy addition of external lock in the laser installation
Manual reset	Not required						Manual reset needed when a power outage occurs or remote lock switch was tripped
Starting with a key	Not required					The laser device does not work when the key is missing
Device warning about emission	Not required				Provides visual or audible warning when the laser is turned on or the battery of the pulse laser is being charged. Applies to 3R class only when invisible radiation is emitted
Attenuator	Not required					Allows to temporarily block the beam
Position control	Not required				Controls are located in such a way that there is no risk of exposure to GED higher than class 1 and class 2, when adjustments are made
Visual optics	Not required		Emission from all visual systems should be below GED for 1M class
Label with class	Inscription required		Labels and inscription required
Label for outlet opening	Not required				Required
Service access label	Not required	Required according to the class of available radiation
Lock removal label	Required under certain conditions, according to the laser class
Information for user	Operating instructions should include recommendations for safe use. Additional requirements apply to 1M and 2M class
Employees training	not required	recommended	not required	recommended	required	required	required
Personal protection equipment	not required	not required	not required	not required	may be required	required	required
Preventive measures	none	avoid the use of magnifying or focusing optical instruments	avoid looking into the beam	avoid looking into the beam and the use of magnifying or focusing optical equipment	prevent looking into the beam	prevent eye exposure to direct and reflected beam	prevent eye and skin exposure to direct and reflected beam
Use of warning signs	not required	not required	not required	not required	not required	required	required
Appointing a laser safety inspector	not required	not required	not required	not required	recommended in the case of invisible radiation emissions	required	required

1 Further proceedings regarding machines where laser equipment is used

1.1 Hazard identification

Type of existing hazards to human health when operating laser devices depends on the laser device safety class. Laser devices are divided into seven classes: 1, 1M, 2, 2M, 3R, 3B, 4, and each class corresponds to the description allowing its identification. The higher the class of a laser, the higher the risk.

Table 3.1. Hazards related to the use of laser devices

Laser class	Identification of hazards related to laser use
1	Lasers emitting visible and invisible radiation, considered safe for use under all reasonably anticipated conditions of use, also when the beam is viewed with optical instruments
1M	Lasers emitting visible and invisible radiation that are safe for use under all reasonably anticipated conditions of use, but may be hazardous when a user inserts optical instruments into the beam
2	Lasers emitting visible radiation. In this case eye protection is ensured by natural aversion reaction of the eye. Due to the natural aversion response such lasers are deemed safe for use under all reasonably anticipated conditions of use, also when viewed with the aid of optical instruments
2M	Lasers emitting visible radiation. In this case eye protection is ensured by natural aversion response, including blink reflex. However, looking with the aid of optical instruments into radiated beam may be hazardous for a user.
3R	Lasers emitting visible or invisible radiation that is potentially hazardous when looking directly into the beam, however, the risk here is lower than for Class 3B lasers. Requirements for manufacturing and control measures to be taken by the user are also less restrictive than for Class 3B lasers.
3B	Lasers which emit visible or invisible radiation that is usually hazardous if the eye is exposed directly. Dispersed reflections, however, are not harmful as a rule.
4	Lasers which emit visible or invisible radiation that is usually hazardous if the eye is exposed directly, and which may disperse reflections causing hazards. May cause skin injury and pose a risk of fire. Their operation requires special attention

Laser classes correspond to the specific requirements regarding the use of safety measures, which should be taken into account when assessing the risk.

Risk assessment

Risk assessment of different classes of laser devices:

· In the case of lasers of 1, 1M, 2, 2M and 3R classes, when they are used in accordance with their purpose and manufacturer’s recommendations and no housing was removed, it can be assumed that the risk related to the hazard to the health caused by laser radiation is negligibly small; in the case of used machines it is recommended to periodically check, against the checklist, if all requirements for a given class are still met.

· Lasers of 3B and 4 classes cannot be used without prior risk assessment taking into account the hazards related to reflected radiation. It is recommended to check against the checklist if all requirements for this class are still met and if there is no hazard related to reflected radiation, e.g. due to changes in technological process or the type of workpiece.

Some of the aspects of hazard identification and risk assessment will be the same for all laser devices, regardless of their class, and with a higher level of laser class it is required to check more aspects affecting the potential hazards.

The proposed method for carrying out a risk assessment is based on filling in the checklist, and carrying out the risk assessment on that basis. If the response on the checklist is “YES”, then the recommended level of potential risk is indicated next to the item.

Three levels of risk classification are used: negligibly small, average (acceptable, but it is advisable to introduce corrective actions) and high (unacceptable, it is necessary immediately introduce corrective actions).

The final risk level is the highest risk level determined. Then, a risk reduction to low level is implemented for all non-compliances identified in the checklist.

If there is no “NO” response in the checklist, the assumed risk is low.

The risk assessment diagram is presented in fig. 3.1.

Laser device

High

Average

Low

Risk

Recommended actions

In order to reduce the risk to small level — in accordance with individual items on the checklist for which non-compliances were found

Immediate action needed in order to reduce the risk to small level — in accordance with individual items on the checklist for which non-compliances were found

Periodical reassessment of the risk in a defined time within 2 years

Special checklist:

- partial risk assessments

Final risk assessment (max. risk from assessments

Initial checklist:

- partial risk assessments

- final risk assessment (max. risk from assessments

Periodic checklist:

- partial risk assessments

- final risk assessment (max. risk from assessments

Risk assessment — special

Initial risk assessment

Periodic risk assessment

Figure 3.1. The procedure for assessing the risks associated with the use of laser devices.