Safety and Standards

Learn about basic laser safety standards and installation precautions here.

Laser Safety Standards

21 CFR Part 1040.10 and 1040.11
International organization
IEC 60825-1
"Safety of laser products"

About IEC 60825-1

What is the IEC?

The IEC (International Electrotechnical Commission) is an international organization that prepares and publishes standards for all electrical, electronic, and related technologies.

What's the IEC's laser safety standard?

IEC established an international standard "IEC 60825-1" for laser products, which serves as a common safety standard for IEC member countries.

About FDA (CDRH)

What's the FDA?

The FDA (Food and Drug Administration) is a branch of the HHS (Department of Health and Human Services). The CDRH (Center for Device and Radiological Health), a division under the FDA, conducts administrative operations of radiological regulations. For production, sale and distribution of laser products in the U.S., manufacturers must comply with the requirements of these regulations.

What's the FDA's laser safety standard?

Title 21 "Radiological Health" of the CFR (Code of Federal Regulations) stipulates regulations on radiation (including lasers) as well as general rules.

Laser Safety Measures * Safety measures based on IEC 60825 Series

General laser safety


Laser safety standards exist to prevent laser-related injuries. It's important that users correctly recognize the potential hazards of laser products and only use them in the manner specified by the safety standards.

Laser safety preventive measures

About laser safety preventive measures

Laser manufacturers and laser users are the primary groups involved with laser products. Users are classified into laser safety control personnel and operators. An outline of safety measures required for individuals is as follows:

The manufacturer's responsibility:

  1. Classify laser products
  2. Take technical measures depending on the laser class
  3. Offer necessary technical information

The user's responsibility:

  1. Establish preventative safety measures
  2. Implement preventative safety measures
  3. Train the operators

Laser Product Classifications

IEC 60825-1

Based on the laser safety requirements specified in IEC60825-1 and FDA (CDRH) 21CFR Part 1040.10, KEYENCE laser markers are classified as Class 4/ Class IV Laser Products.

IEC standard

Laser class Class Definition
Class 1 Laser products that are safe to use. This includes long-term intrabeam viewing, even when exposure occurs while using optical viewing instruments such as eye loupes or binoculars.
Class 1M Laser products that are safe for long-term, direct intrabeam viewing by the naked eye (unaided eye). Eye injury may occur when viewing the beam while using optical viewing instruments. The wavelength region for Class 1M lasers is restricted from 302.5 nm to 4,000 nm.
Class 2 Laser products that emit visible radiation from 400 nm to 700 nm. These products are safe for momentary exposures but can be hazardous if you deliberately stare into the beam. Using optical instruments does not increase the risk of ocular injury from a Class 2 laser.
Class 2M Laser products that emit visible beams of light and are only safe for short exposures to the naked eye (unaided eye). Eye injury may occur when using optical viewing instruments to view a Class 2M laser.
Class 3R Potentially hazardous laser products with a relatively low risk of injury. The chances of injury increase with the exposure direction, and direct ocular exposure is hazardous.
Class 3B Laser products that are hazardous when intrabeam ocular exposure occurs (including accidental short exposures). Viewing diffuse reflections is normally safe.
Class 4 Intrabeam viewing of Class 4 lasers is hazardous, as is skin exposure. Viewing diffuse reflections may also be hazardous, and these systems often represent a fire hazard.

FDA standard

Laser class Class Definition
Class I Class I laser radiation is not considered hazardous.
Class IIa Class IIa laser radiation is not considered hazardous if viewed for any period of time less than or equal to 1x103 seconds, but is considered a chronic viewing hazard for any period of time greater than 1x103 seconds.
Class II Class II laser radiation is considered a chronic viewing hazard.
Class IIIa Class IIIa laser radiation is, depending upon the irradiance, either an acute intrabeam viewing hazard or chronic viewing hazard. If viewed directly with optical instruments, Class IIIa laser radiation is classified as an acute viewing hazard.
Class IIIb Direct Class IIIb laser radiation is considered an acute hazard to the skin and eyes.
Class IV Class IV laser radiation is considered an acute hazard to the skin and eyes from both direct and scattered radiation.

Safety measures/equipment for laser markers*

These KEYENCE laser markers have the following safety measures.

Key Control

A key-operated power switch is required to start up the laser controller. Remove the key when the laser system is not in use.

Key Control

Laser radiation emission warning

When the key-operated power switch is turn to [LASER ON], the marking unit enters a state in which the laser can oscillate and the laser radiation emission indicator lights up.

A laser radiation emission indicator is located on the top of the marking unit and in front of the controller unit.

Laser radiation emission warning

Laser shutter

A safety shutter inside the marking unit automatically closes to prevent laser beam emission.

Remote interlock (Emergency stop) input terminal

The remote interlock (emergency stop) inputs are redundant.
Opening either terminal halts laser emissions and stops all marking operations.
Short-circuiting both terminals makes laser emission possible.
The terminals are shorted with a metal bar at the time of factory shipment.

For the MD-X/MD-F/MD-T/MD-U, terminal A14 is the emergency stop input A and terminal 12 is the emergency stop input B.

Warning Labels

Warning Labels

For other series, refer to the appropriate user’s manual.

* The following warning labels, explanatory labels, and aperture labels are attached to the marking unit of the laser system.

WARNING LOGOTYPE (FDA warning label)
Warning/Explanatory/Aperture label (Japanese)
Warning/Explanatory/Aperture label (English/German)
Warning/Explanatory/Aperture label (Chinese)
Attachment positions
Warning/Explanatory/Aperture label (Thai)

User's Guide

Take the following safety measures when using Class 4 laser products from KEYENCE.

Use the Remote Interlock (Emergency Stop) input terminal

Connect the remote interlock terminals to emergency stop switches or the like to prevent laser radiation in an emergency.

Manage the key to the power switch

To prevent operation of the laser system by unauthorized users, the key should be managed by the Laser Safety Officer.

Setup a warning indication sign and a controlled area

Post a warning sign at the entrance to the area in which the laser product is installed to ensure that workers and outsiders are informed of the danger.

Terminate the beam path

Class 4 systems must be installed in a way that reduces the possibility of unintentional laser radiation on any object. This includes the marking target or a machine/machine part, and must be true for both normal operation and foreseeable fault conditions.

To avoid eye and skin exposure to direct or scattered laser radiation, the laser beam emitted by the laser system must be terminated at the end of its useful path by a diffusely reflecting material of appropriate reflectivity and thermal properties (or by absorbers).

Protective Clothing

If skin is exposed to a laser beam that's reflected off a marking target, the skin will burn and clothes may catch fire. Wear flame-resistant clothes and protect the skin as much as possible while operating a Class 4 laser.

Eye protection

Wear protective eye gear in the area in which the laser is installed in case of accidental exposure to laser emission. You should wear goggles during normal laser operation and when performing laser maintenance.

Protective goggles

Select protective goggles that are appropriate for the laser light wavelength.

  • CO2 laser (wavelength: 10.6 μm, OD: 5-7)
    (ML-Z Series)
  • YVO4 laser (wavelength: 1064 nm, OD: 5-7)
    (MD-X Series)
  • Fiber laser (wavelength: 1090 nm, OD: 6 or more*)
    * The laser emission warning can be confirmed.
    (MD-F Series)
  • UV laser (wavelength: 355 nm, OD: 6 or more)
    (MD-U Series)
Recommended protective goggles

Note: Protective goggles are intended to protect eyes from scattered light. Never use protective goggles against exposure to direct or reflected light.

Acrylic filter

Laser light can be blocked by attaching an acrylic filter to the monitoring window on the equipment, the protective enclosure or the observation window on the protective cover.

Use a local ventilation system

If poisonous gas is generated during laser marking on a target object, identify the substances produced by the gas and provide a local ventilation system.

Appoint a laser safety officer

Appoint a safety officer who has knowledge and experience in handling laser products in order to enforce safety management. The responsibilities of the Laser Safety Officer are as follows:

  1. Suggest prevention measures related to laser emission
  2. Set up the controlled laser area (area in which there is a risk of exposure to laser emission)
  3. Manage the key for the key-operated power switch
  4. Check the protective equipment and its use
  5. Train operators

Installation example

The following example is for ML-Z Series. For other series, refer to the appropriate user’s manual.

For marking from the top
For marking from the side
For marking from the bottom

Protective Enclosure

Establish a protective enclosure around the laser marker's head using material with the appropriate reflectance and heat characteristics needed to block reflected laser light. Doing so prevents individuals in the vicinity of the laser marker (or the laser's controlled access location) from being exposed to careless reflected light.

Safety Precautions

Follow the instructions mentioned in KEYENCE's laser safety guide. Using controls or performance procedures other than those specified may result in hazardous radiation exposure.

The following example is for ML-Z Series. For other series, refer to the appropriate user’s manual.

Do not expose your eyes to laser radiation or diffuse reflection.

Exposing your eyes to laser radiation or diffuse reflection may cause blindness.

Do not expose your skin to laser radiation or diffuse reflection.

Do not insert a hand or other body part into the marking area during operation. Doing so may damage and burn your skin.

Identify the hazardous area of your laser marker (while the laser is actively marking).

If part of your body enters this range, your skin or eyes may be damaged. Similarly, any objects entering this range may catch on fire.

Considering the hazardous characteristics of Class IV systems, make sure to completely enclose your laser marker's hazardous area with the proper materials.

Terminate the laser beam path when installing the laser marker head.

The beam emitted from KEYENCE laser markers must be terminated at the end of its useful path by materials or absorbers with appropriate reflectivity and thermal properties. If the beam is not terminated, there's a risk of exposure to direct and scattered laser radiation.

5. Wear protective eye goggles appropriate for the laser beam wavelength.

Wear protective eye gear with the appropriate optical density for your laser marker's wavelength. Do not wear protective eye goggles with an optical density exceeding 7, otherwise the laser radiation emission indicator may not be visible.

Even with adequate protective gear, you should still avoid eye exposure to direct and scattered laser radiation.

Do not disassemble KEYENCE laser markers.

Electrical shock and exposure to laser radiation may occur if a KEYENCE laser marker is disassembled. A system's warranty is void if non-KEYENCE personnel takes it apart.

Use a protective enclosure to fully cover the area in which the laser will be emitted.

A protective enclosure must have proper reflectance and thermal characteristics. It must also be able to terminate the laser beam path. Otherwise, unintentional exposure to laser radiation may occur if the beam penetrates through the enclosure.

Do not install KEYENCE lasers so that the beam is at eye-level.

Take necessary maintenance precautions.

Turn off a KEYENCE laser marker before performing maintenance
Always wear protective goggles during maintenance

Do not use KEYENCE laser markers near flammable materials

Do not place any flammable objects or gas (organic solvents) near the laser emission. This may cause a fire.

Do not irradiate a CO2 laser beam onto mirrored metal surfaces.

CO2 lasers cannot mark metal materials. Never attempt to mark highly reflective metal materials with a CO2 laser marker.

ZnSe (zinc selenium) is used for the laser lens and other optical parts.

ZnSe is treated as a poison by law. Rely on a company that handles industrial waste when disposing of the product.

Make sure the laser power is OFF before connecting the controller power cable.

Otherwise, it may cause an electric shock.

Use a dust/fume collector to eliminate the particulates that occur during marking.

Depending on the target material, the generated particulates may cause damage to the human body.

Do not use KEYENCE laser markers in any way that is not described in their respective manual.

Otherwise exposure to unintentional laser radiation may result.

Laser Safety Terminology

These are some common safety terms concerning laser products.

Diffuse reflection Light that scatters in multiple directions after a beam reflects off a surface or medium.
Specular reflection Light that can still be considered a beam after reflecting off a surface (including mirrored surfaces).
Nominal Ocular Hazard Distance (NOHD)

The distance in which the beam irradiance (radiant exposure) from the laser equals the maximum permissible exposure (MPE) of a human cornea.

Since a laser beam has a divergent angle, its spot diameter becomes larger the further the beam is from its focal point. As a result, the energy applied in a unit area is reduced.

Nominal Ocular Hazard Area The area within which the beam irradiance (radiant exposure) exceeds the appropriate maximum permissible exposure (MPE) of a human cornea.
Maximum permissible exposure (MPE) The level of laser radiation to which, under normal circumstances, persons may be exposed without suffering adverse effects.
Accessible Emission Limit (AEL) The maximum accessible emission permitted within a particular laser class.

Effects of a laser beam on the human body

Harmful effects

Human bodies exposed to a laser beam may suffer protein denaturation due to the laser's heat, and/or photochemical reactions caused by impact waves (plasma flow and pressure waves) that destroy cell tissue.

Specific biological effects depend on a laser beam's wavelength, output and waveform (continuous vs. pulse). In general, laser light is more likely to cause serious, irreversible damage to the eyes rather than the skin.

Laser markers generate harmful dust and debris while marking a target, so extra care should be taken to make sure no foreign particulates enter the human body.

Eye problems

Argon, YAG and CO2 lasers all radiate continuous or long pulse waves. These systems can cause problems due to heat effects or photochemical reactions.

  1. Laser beams with UV (200 to 400 nm) and IR (1,400 to 106 nm) wavelengths are absorbed in the tissues of the cornea or lenses, causing cataracts with corneal burns and/or visual degradation.
  2. Laser beams with visible (400 to 780 nm) and near-IR (780 to 1,400 nm) wavelengths affect the eye's retina.

Laser beams that produce continuous waves are absorbed in the retina and mainly cause retinal burns due to heat.

Laser beams that can be seen (and are around 430 nm) cause retinal problems due to photochemical reactions. This is because that particular wavelength is absorbed in the visual pigments of retinal photoreceptors.

YAG/YVO4 lasers and CO2 lasers - which have a short pulse duration and high peak power - can cause retinal burns or fundal hemorrhage, often resulting in severe visual degradation.

Eye absorption Wavelength range specified by the CIE (nm) Effects or problems caused to eyes
Range of perception

Severe corneal or retinal pain due to inflammation caused by photochemical reactions or heat effects.

Lens opacification (cataracts) due to heat effects.

Retinal problems due to the photochemical reactions caused by visible light, or retinal damage caused by heat effect or impact waves

Corneal burns or cataracts due to heat effects.

* The CIE stands for the Commission Internationale Enluminure (International Commission on Illumination)

Skin problems

Mild erythema, blisters and carbonization occur on human bodies that are excessively exposed to high-power laser beams.

* According to a notice issued by the CDRC on preventative measures against problems caused by a laser beam