Are Laser Cutters Dangerous?

Laser cutters are extremely dangerous. Don’t use them. Go home… 🙂

All kidding aside, since laser cutting machines are very powerful and designed to slice through quite a number of materials, it makes sense that something wielding that much power will require an exercise in caution.

So to answer somewhat common question: are laser cutters dangerous? The truth is that, like many things in life, laser cutting machines will pose a serious threat if and only if the necessary precautions are not taken before, during, and after operation. There are definitely certain risks associated with laser cutters like the potential for toxic fumes (some of which are known to be carcinogenic or irritant to the lungs in other ways), fires, and physical bodily injury that are not associated with other kinds of cutting machines like die cutters. Luckily, there are some quick simple ways to avoid these hazards and to cut projects cleanly and exercising the best practices in safety

Read on for some brief but important tidbits of information. I will discuss the different classifications of laser beams as well as exactly which kinds of laser beams emitted pose the greatest danger risk (as it pertains to the different classes of lasers).

I will also go into what are some common overlooked risks associated with many laser cutting machines as well as steps you can take that can easily prevent many mishaps.

Classification of Laser Light

Laser cutters have been in existence since the mid-1960s. Initially fiber lasers were used to cut metal exclusively.This use was the norm for a number of years.

Later on in the 1970s, CO2 lasers were invented that would allow for the cutting of thinner materials and other materials that were not comprised of metal like fabrics.

Since that time three main kinds of lasers have been in existence: fiber, CO2, Nd (Neodymium) Nd:YAG (Neodymium-doped yttrium aluminum garnet). CO2 lasers are the most popular type since they can cut such a wide variety of materials, not only metals.

All of the desktop laser cutting machines I’ve seen so far have been CO2.

Right around this time, United States federal regulations and international standards were put into place to define classes of lasers depending on their maximum output power and wavelength.

The purpose of these regulations was to impose on manufacturers certain standards of safety. An example would be to provide specific warnings, such as the requirement of wearing safety goggles, enforcing special operating procedures to avert any hazards that may arise, and to establish certain control measures measures helpful in calculating maximum permissible exposure limits.

Laser beams are subdivided into specific classes: class 1, 1M, 2, 2M, 3R, 3B, and finally the most powerful and dangerous of all lasers, 4.

Note: There are a number of specific technical qualifiers for these classes that are quite a bit more involved and detailed than what I will go into. I will just give you the basic gist of how these lasers are classified so as not to bore you too much.

Class 1

Class 1 lasers are the safest of them all under normal use. In order for a laser to be classed as class 1, it’s maximum permissible exposure should allow one to be able to view the beam of light with the naked eye. You typically see these kinds of razors in optical disk drives.

Class 1M

Class 1M lasers are safe in all conditions except for when they are passed through magnifying devices like telescopes and microscopes. This class of lasers emits some radiation.

Class 2

Class 2 lasers are fairly safe, although special precautions need to be taken. One should not stare into the beam as it can cause some damage to the eyes.

I remember back in the late 90s laser pointers were all the rage in my high school. I had one that would drive my dog crazy.

I remember I was also stupid enough (I’m sort of embarrased to admit) to point the thing directly into my eye just for good measure to see what would happen…


Luckily I didn’t cause any long-term serious damage to my retinas, for I didn’t stare into the beam long enough.

In any event, your typical run-of-the-mill laser pointers that can be purchased in gift shops and office supply stores are usually classified is class 2.

Class 3R

Class 3R lasers emit some radiation. Although reasonably safe when handled carefully, considerable caution needs to be taken when operating machines using these lasers. You will want to avoid direct eye exposure to this laser is much is possible.

Class 3B

Protective eyewear is usually required when operating machines using this wavelength of laser. Diffuse reflections from the emitted laser beam may be OK, but direct exposure to the eyes is hazardous and must be averted.

And finally we will get to class 4 lasers…

Which Classes of Lasers Are The Most Dangerous?

Class 4

Class 4 lasers are the most dangerous of all the classes. In addition to emitted radiation, eye exposure to any degree, skin exposure, and also even any indirect scattered radiation from these laser beams must be avoided at all times.

These lasers are typically powerful enough to ignite certain materials that are combustible. Even the reflections from the light emitted from these beams is also dangerous. The surfaces around the laser must therefore be of a matte surface rather than reflective.

When you think of a laser beam you’re probably thinking of one that emits visible light. However, if you remember from your grade school science classes, visible (to humans) light is just a very small slice of the electromagnetic spectrum.

Laser cutters are also capable of cutting using infrared and ultraviolet light, which has already explained is invisible to human beings. Since these are invisible, some care should be undertaken when operating machines using these wavelengths of light.

What Are Some Risks Associated With Laser Cutting Machines?

I already mentioned how dangerous class 4 laser beams are. This should already go without saying.

Any laser beam that is powerful enough to cut through materials would be dangerous if you were allowed to escape the cutting machine. So beam escape could possibly be a minor issue, although most machines are well designed to be able to contain the laser.

But there is a much greater concern for anyone using laser cutters…

Toxic Fumes

Quite possibly the greatest issue and often a silent and easily overlooked risk when using laser cutting machines is the toxic fumes and exhaust that could be emitted while the machine is either engraving or cutting materials.

Not to be alarmist or anything, but the following linked article is a sad precautionary tale published from The Register some years back. 

This happened to a young couple simply because they failed to follow the necessary basic safety measures when operating even a desktop laser cutting machine.

Never be cavalier about fumes and safety. Ever.

All materials cut with laser cutters will release some volatile organic compounds even if the materials they are cutting are designated is “safe”. A laser cutter will naturally give off some dust which can cause respiratory problems.

Filtration is therefore not an option when operating these machines! They will all need one or more of the following:

  • Charcoal or HEPA filter
  • Air duct to allow exhaust to escape to the outdoors
  • Fume extractor to allow for the machine to be used safely indoors

Any enclosure where laser machines will be used to frequently requires proper indoor ventilation (HVAC systems), and needs to have a large enough area so that exhaust is not too concentrated.

See my earlier article What Can A Desktop Laser Cutter Cut for a more detailed list of materials that are hazardous when used with a laser.

Fire Risk

Although laser cutting machines are designed to cut through and engrave numerous materials, and risk of fire damage is relatively low, there are a number of materials that are combustible and therefore should be avoided completely.

Polystyrene foam Will either melt completely or is prone to catch fire. Another material is ABS. In addition to it’s slightly higher chance of catching fire, it can also leak cyanide gas!

Some Safety Steps

A good rule of thumb for safety purposes is to always keep vigilant during operation of your machine.

Make sure there are no flames that remain after the laser is done cutting the material(a small temporary flame not much larger than the laser meeting the material being cut is typical).

Keep a fire extinguisher nearby, and of course be prepared to call 911 if there is any major emergency. Just common sense stuff.

Always follow the instructions listed by the manufacturer of your machine carefully.

Always keep the surrounding areas as well as inside of the laser machine well-maintained and cleaned regularly. Make sure there is no dust buildup or debris that has accumulated on the floor and especially near the laser. This is just best practices in general, but also aids in preventing fires.

Never be adventurous and try to cut or engrave anything in your machine that it is not designed to cut or that you’re not sure if it will cut, e.g. food, materials with filaments, etc.

Keep in mind that even some kinds of wood might contain fillers in materials embedded in it that are not safe to cut in your machine. Always know where your material is being sourced and what exactly it is that you’re cutting.

Stay away from pallet wood. It could contain nasty carcinogens, toxic chemicals, other things like methyl bromide. 


As long as you follow the instructions for your machine given by your manufacturer, don’t cut any hazardous materials, follow necessary safety precautions, and allow for proper ventilation perfumes emitted by your machine, you should have no problems using your machine safely and cleanly for a long period of time.