Your laser cutter is a very useful tool that can create some amazing items. As you learn to use it, you will become more creative and be able to experiment with an ever-increasing range of materials and designs — whether cutting engraving, or a combination of both. However, there are several laser safety hazards associated with the home laser cutter that can raise laser cutting health concerns and they need to be fully understood before you start. This laser cutter safety article should help you understand all of the laser hazards and allow you to operate your laser cutter safely — not only for yourself but also for those around you.
How a Home Laser Cutter Works
Almost all laser cutters contain a Laser Hazard Class 4 device, which means they are quite powerful and can cause permanent injury, so an understanding of how they work will help you understand and manage laser safety risks.
The CO2 laser cutter uses a glass tube that is filled with inert gasses and connected to a very high voltage power supply. The light is generated inside the glass tube and laser radiation is emitted from one end and then bounced off a series of mirrors until it reaches the laser head, where it is focused down to a tiny dot on the workpiece being cut or engraved.
The head is mounted on rails that are moved by powerful servo motors so that the laser can cut or engrave the design.
A Diode Laser works similarly except that the blue or green laser radiation is created by a semiconductor diode and a Fiber Laser uses a semiconductor and optical fiber combination to create the IR light source but then uses a single mirror that is moved by a set of servo motors.
Are Home Laser Cutters Safe to Operate?
Yes, home laser cutters are safe to operate. While there is a laser hazard present, home laser cutters are designed with many safety precautions to minimize laser cutting health concerns. As long as you take the correct precautions, home laser cutters are quite safe. When it comes to laser safety, it's the responsibility of the user to know the relevant laser dangers and utilize the necessary PPE for laser cutting. Read the user manual and carefully observe all of the laser safety measures. Over time, you will get used to a regular procedure of setting up and running the laser safely.
When do most injuries occur when working with laser cutters?
Most laser cutter-related injuries occur during laser mirror alignment. Laser mirror alignment is when the laser mirrors are being aligned. There is a great temptation to operate the laser with the cabinet door open, the safety interlock disabled, and hands moving around inside the cabinet. This is a highly dangerous practice and should be avoided. It only takes a few extra seconds to close the lid and operate the laser safely. Even the biggest laser safety threats can be mitigated with the correct precautions.
Visible light is electromagnetic radiation with a wavelength between 400 and 700 nanometers (nm). That might not mean a lot to you, but the changing wavelength generates different behaviors in materials and is what causes your eyes to see different colors as that light hits the retina. The rainbow, for example, ranges from 420nm to 680nm — what we refer to as “visible light”. Outside of these numbers, light is referred to as Ultraviolet (UV) at the low end and Infrared (IR) at the top end.
How Laser Light Works
Anything that generates light, such as your household lightbulb or the sun, produces light in all directions and typically with a range of wavelengths. This is how we see and observe what is around us. Laser devices, however, generate an intense beam of laser radiation that is all traveling in the same direction and with almost all of the light being of one specific wavelength.
A green diode laser is 532 nm, while a Fiber Laser is between 780 nm and 2200 nm. A CO2 Laser is 10,600 nm.
Laser Radiation Safety
What is Laser Radiation?
All lasers emit radiation in the form of light. In fact, a laser beam itself is a form of radiation, as the word laser is an acronym for Light Amplification by Stimulated Emission of Radiation. You don’t need to spring for your Geiger counter, however, as today’s home laser cutters are not nuclear-capable.
The term laser radiation doesn’t typically refer to the actual laser beam. Laser radiation occurs when the laser beam strikes an object and the object’s surface does not fully absorb the laser beam; some of the light energy is reflected or refracted back in random directions. This type of laser radiation can be hazardous, and even seemingly matte materials, such as wood, can produce harmful laser beam reflections.
Is Laser Radiation Harmful?
Laser radiation, because of its wavelength and the concentrated beam that is generated, can be harmful. The main threat that laser radiation poses is to your eyes. However, when proper laser safety procedures are followed, you should remain completely free from laser radiation while operating your laser engraver machine. Additionally, laser hazards can vary depending on the type of laser.
Different Types of Laser Engraver Hazards
Diode Laser Hazards
The most hazardous laser radiation is that generated with a blue or green diode laser. Diode laser light at 532 nm is not blocked by transparent materials such as the lens of the eye but passes through it until it meets the retina. The retina absorbs the energy from the laser light and is damaged irreversibly. This can happen in less than 1/1000th of a second, faster than the eye can blink. Blue laser light is more damaging than green although both can cause permanent damage to the eye.
CO₂ Laser Hazards
CO2 lasers generate laser light at a wavelength of 10,600 nm which is right up in the infrared (IR) spectrum. Unlike the blue/green diode laser light, this is completely invisible which means that extra care must be taken, however, it is also blocked by almost all materials including the lens and cornea of the eye. When IR light hits an object, it heats that surface up. This is how the CO2 laser cuts and engraves, by heating the surface until it vaporizes. However, it does take a small amount of time for the material to absorb enough light energy for this to happen and so whereas an indirect flash from a reflected blue/green diode laser can cause immediate laser cutter eye damage within 1/1000th of a second, the same from a CO2 laser is less likely to cause permanent damage. However, all laser light is hazardous and following the safety advice is essential. Looking directly at a laser radiation source will cause permanent eye damage.
How to Laser Engrave Safely at Home
Most home laser cutters are rated as laser safety Class 4, the highest laser hazard class, meaning the device is hazardous. Before you start, always read the manual, especially the Laser Hazards safety sections, and observe the warning labels on the machine. Make sure that you understand exactly how your laser machine operates so that you can avoid hazards and minimize any unnecessary risks. When used as designed, the laser cutter safety is considered Class 1 - safe for operators and bystanders.
Where to Set Up Your Home Laser Cutter: Environment Conditions
One important factor is where to locate your Laser Cutter. Your user manual will give you any specific things to bear in mind, however generally the chosen locations should be:
- Stable, level, dry, and climate-controlled with an ambient temperature of 40–75°F
- Ambient humidity under 70% and not close to the dew point (to avoid condensation).
- Out of direct sunlight
- Free of dust and other airborne pollutants
- Well ventilated
- Away from children; combustible, flammable, explosive, or corrosive materials; and sensitive EMI devices.
- The power cord should be plugged into a stable power source with a grounded 3-prong outlet. No other item should be drawing current from the same fuse.
- Keep fire-fighting equipment nearby.
- Keep an extra work table nearby to avoid placing objects on or directly adjacent to the machine, which could become a fire or laser hazard.
Laser Cutter Eye DamageIs it safe to look at a laser engraver?
The answer is that it depends. You must never look at a green or blue diode laser without wearing the correct Laser Safety Goggles, however, a CO2 laser is perfectly safe when operating correctly with the cabinet doors closed and following the laser engraver safety rules. However NEVER look directly at a laser beam — it will cause permanent eye damage.Can a laser engraver hurt your eyes?
A blue or green diode laser can certainly inflict permanent damage to your unprotected eyes, however, a CO2 laser is perfectly safe when operating correctly with the cabinet doors closed. Both types of laser can permanently damage your eyes and other parts of your body if you hypothetically took a direct hit from the laser beam — so always follow the laser engraver safety rules.Which Laser Safety Glasses should I buy?
If you are using a blue or green diode laser, then laser safety goggles are made for these, specific to the frequency of the diode being used. It is essential that you use the correct ones. CO2 laser safety glasses are made in a much wider range of styles and are made from polycarbonate — the same material that the viewing window of your laser machine is made from. This absorbs the IR laser light.What protective glasses should I use with a laser engraver?
Laser Safety Glasses should be made to either ANSI Z136 or EN207/208/60825 standards. Good Laser Safety Glasses have an Optical Density (OD) of at least 4 and preferably 6+.
Note that Safety Glasses are meant to protect you against incidental laser light that might be reflected off a metal surface. They are not designed to protect you from looking directly at a laser beam so never, ever, look directly at a laser beam.Laser Safety Hazards for Diode Lasers
If you are using a diode laser, then specific laser safety glasses for laser engraving are essential at all times. These must be specific to the frequency of the diode laser being used and need to completely envelop the eyes. Laser cutter eye damage can occur in a fraction of a second and is permanent. Steps must be taken to exclude people and animals from the room being used whenever the diode laser is in use. Each operator must have their own PPE for laser cutting such as Laser Safety Glasses to prevent laser cutter eye damage.Laser Safety Hazards for CO₂ Lasers
CO2 lasers pose slightly less of a problem as long as the standard laser safety systems are in place. Your CO2 laser is built into a metal box with a clear polycarbonate window. The polycarbonate will block the IR laser light when the lid is closed. A safety switch is built into the lid which stops the laser from firing if the lid is open. Although there may be an override switch on the control panel, it is highly recommended that the safety is not switched off. If you do need to disengage it, then you must wear approved Laser Safety Glasses specific to the CO2 laser light wavelength and exclude people and animals from the room being used.
As CO2 laser radiation is completely invisible and is being bounced around inside the laser cabinet, the potential for extremely painful burns to hands and fingers remains whenever the lid is not closed when the laser is operating.
Your laser room should also be protected with suitable Laser Safety warnings for others. Ensure that appropriate warning signs are visible and especially for diode lasers, make sure that there are laser safety goggles available before someone enters the room.
When used with the appropriate safety precautions, Laser cutters are safe and are considered Class 1 - safe for operators and bystanders. Operating them carelessly and without regard to the inherent dangers that exist will potentially cause life-changing injury.
Electrical Laser Safety Hazards
The CO2 laser cutter works with extremely high voltages, some in excess of 25,000 volts, and these voltages are lethal. These high-voltage areas are protected by cabinet doors and these must remain closed whenever the laser is switched on. An emergency stop button is provided to immediately isolate any voltages but if you plan on working inside the electronics cabinet, it is highly recommended that you disconnect the laser from the mains.
One of the main potential problems with the high voltage system is when the laser is located where it is subject to a build up of condensation. This can cause the wiring and connectors to arc and short out. Always remember to check the laser cutter for any signs of condensation before you start using it and ensure that the room is suitably conditioned (heating, ventilation) to prevent condensation from forming. An arcing high voltage system will produce a snapping sound when the laser is operating. Switch off the laser immediately before isolating and resolving the problem.
Safety precautions for flames and burning
Can a CO2 laser engraver catch fire?
Depending on the flammability of your workpiece, it is possible for your laser engraver to catch fire. Your CO2 laser fires its focused laser beam onto the workpiece which then vaporizes the material. At low power or high speed, this can just engrave the surface, or with some materials, a higher power or slower speed will actually cut through it. On flammable materials such as wood, cardboard, etc, the edges of the cut may burn rather than vaporize.
That's why the laser engraver is fitted with an air pump that prevents the material from igniting. Normally, the airflow through the nozzle is sufficient to ensure that the flame does not take hold. But if the air pump fails or a pipe becomes disconnected, then the workpiece could catch fire. This is why it is essential to ensure that the air pump is working and that all the pipework is secure. A failure of the air pump or pipework can lead to the material being cut or engraved igniting and a fire may ensue.
One other reason that can lead to a potential fire is if the X or Y axis become jammed such that the laser continues to burn the same point repeatedly. This is a good reason to ensure that you undertake regular maintenance of the laser cutter including cleaning, lubrication, and checking the toothed belts, and keeping the work bed clear of debris, old projects, or anything other than the piece being engraved.
This is one of the primary reasons why you must NEVER leave your laser cutter unattended while in use.
How do you extinguish a laser engraver fire?
If your laser engraver ever catches fire, you can extinguish it by using the emergency stop to disable the laser machine and then quickly cover the machine with a fire blanket to extinguish the fire. Use a fire extinguisher if necessary, and never use a fire extinguisher on a working laser due to the extremely high voltages. Wait for everything to cool down before examining it for the cause and damage.
Safety precautions for mechanical problems
The laser cutter uses several powerful servo motors that move the laser head to engrave or cut the design. Apart from sensors that detect the ends of travel, these motors cannot detect if anything gets jammed. Given the extreme force that they can apply, putting your hands and fingers inside the laser cabinet when it is switched on is extremely dangerous and can cause significant injury. Keep any other items outside of the cabinet, such as tools, additional workpieces and always keep the cabinet doors closed when the laser is switched on.
Laser Engraver Exhaust: Safe Ventilation
Are fumes from laser cutting toxic?
Yes, laser cutter fumes and even the smoke produced by CO₂ laser engravers can be toxic to your health. Even laser engraving and cutting the basic materials like wood and acrylic produces noxious fumes and carbon monoxide. However, most laser engravers are equipped with ventilation systems that remove the fumes to the outdoors where they will quickly dissipate. As long as your ventilation system is set up correctly, any laser cutting odors you might experience do not contain any airborne toxins.
How harmful is laser dust?
Laser dust and smoke are considered to be PM2.5 which means that inhaling them should be avoided. As long as the ventilation system is working efficiently, most of these particles should disperse harmlessly outside and alleviate any laser cutting health concerns.
Can you use a laser engraver indoors?
You can use a laser engraving machine indoors if you have a proper ventilation system in place. Whatever material is being laser cut or engraved will produce smoke and fumes and these must be removed quickly and safely from the laser cabinet. Excessive laser cutter fumes and smoke can condense onto the laser mechanisms causing premature bearing failure and damage to the focal lens and laser mirrors.
While laser engraving at home indoors is possible, it is preferable to use a climate-controlled garage, shed, or other outbuilding. The main issue will be the smell of the material being engraved. Although a good ventilation system will remove almost all of the laser cutter fumes and smoke from the laser cabinet, it is not airtight and some smell will still be noticeable.
How do you vent a home laser engraver?
Your CO₂ laser engraver should come with a ventilation fan near the exhaust port and a flexible ducting hose. Upon initial machine setup, you should connect one side of the ducting to the laser machine’s exhaust port, and the other to a safe exit vent that releases the exhaust to the outdoors. The ventilation fan should be strong enough to push the laser cutting fumes and other airborne debris through the ducting and out your exit vent. However, if you have a large laser cutting workload, you may need to add an inline fan to help suck the exhaust out faster. Always ensure your ventilation fan is switched on before starting the laser. After completion, leave it running for a minute or so to fully ventilate the cabinet and remove all the laser cutter fumes.
The outlet from the fan should exit outside of the building, either through a dedicated outlet or a window and be suitably protected from wind and animal/insect intrusion with a mesh and air flap. Ensure that it is kept away from anywhere where people may pass too closely or congregate. The smell of laser cutter fumes and smoke residue will be noticeable and so be careful not to cause problems with neighbors. Remember that you are responsible for meeting all applicable local and national laws and regulations regarding the ventilation of laser cutter fumes and smoke from your laser.
Pro Tip: For greater efficiency, if you have a long run of ventilation pipework, place the ventilation fan close to the outlet so that the fan pulls air through the longer pipework, rather than pushing it.
Laser Cutter Materials Safety
Your laser cutter can cut and engrave many materials but there are some that you must avoid. If in doubt, look for the MSDS Safety Sheet for that material. As the laser burns and vaporizes it, the Safety Sheet will inform you of any dangerous byproducts released during combustion.
Materials that can be laser engraved and cut:
Ceramics, including Dishes, Tile, etc.
Paper & Paperboard
Stone, including Marble, Granite, River Rock, etc.
Textiles, including Cotton, Suede, Felt, Hemp, etc.
Wood, including Cork, MDF, Plywood, Balsa, Birch, Cherry, Oak, Poplar, etc.
Acrylonitrile Butadiene Styrene (ABS)
Nylon (Polyamide, PA, etc.)
High-Density Polyethylene (HDPE, PEHD, etc.)
Biaxially-Oriented Polyethylene Terephthalate (BoPET, Mylar, Polyester, etc.)
Polyethylene Terephthalate Glycol (PETG, PET-G, etc.)
Polyimide (PI, Kapton, etc.)
Polymethyl Methacrylate (PMMA, Acrylic, Plexiglass, Lucite, etc.)
Polyoxymethylene (POM, Acetal, Delrin, etc.)
Polypropylene (PP, etc.)
*Genuine leather can be safely laser cut or engraved, but ensure that if it has been tanned then it is “veg-tanned” otherwise it will have been treated with chromium salts that will release dangerous particles when laser engraved.
Materials that cannot be laser cut or engraved:
Artificial Leather containing Hexavalent Chromium (Cr[VI])
Chlorine, including Polyvinyl Butyrale (PVB) and Polyvinyl Chloride (PVC, Vinyl, Cintra, etc.)
Fluorine, including Polytetrafluoroethylenes (Teflon, PTFE, etc.)
- Materials with Halocarbon compounds
Phenolic Resins, including various forms of Epoxy
Polycarbonate (PC, Lexan, etc.)
Of particular note is anything made from PVC or Vinyl. Not only are the fumes toxic, but they will also condense inside the laser cabinet and cause rapid and premature corrosion of metal surfaces, bearings, etc.
You can mark metals with a CO₂ laser with the help of a special coating agent. However, you cannot cut or engrave metals with a standard CO2 Laser due to their conductivity and reflectivity. If you want to engrave metal then have a look at the OMTech Fiber Laser range.
Best Practices for Home Laser Safety:
Keep your work area clean and tidy.
Ensure that your laser is maintained and serviced.
Check that ventilation fans are cleaned every 6 months.
Check and replace your cooling water every month and treat it with an algicide.
If others use your laser, keep a logbook on the machine with notes of any problems or issues that you notice.
If you use a home laser cutter around your family, educate your family about the importance of laser safety.
If you have small children or curious pets, keep your laser engraver behind locked doors, if possible — or out in the garage where they won’t be tempted to play with it.
Always keep the magic key that unlocks the laser cabinet locked away safely.
Do not bypass any safety features.
Never get complacent around your laser and try to cut corners.