10 Important Safety Precautions for Laser Cutting
Learn more about the various safety precautions to take when using a laser cutter.
It is important to take safety precautions when using a laser cutter. The high-powered laser can cause permanent eye damage if a person is accidentally exposed. As a result, it is important to be properly trained, wear the correct safety gear, and never bypass any interlocks on the machine. Also, fire is a constant risk during laser cutting, so fire safety precautions are always critical. Listed below are 10 important safety precautions for laser cutting:
Proper training is key when using a laser cutter. Laser cutters include dangerous components, and it is important to know and understand the risks. The device’s manufacturer can often provide training. Training should cover the general hazards of laser cutting in addition to the detailed procedures and interlocks of your specific machine. New operators must also receive training and refresher courses at predetermined intervals.
Safety interlocks in laser cutters are integral to their functionality. The lasers themselves are usually Class-3B or Class-4 lasers. These classes are powerful enough to cause eye injuries if viewed directly (and sometimes even indirectly) and can potentially cause skin damage or fire.
Due to the interlocks built into the laser cutter, however, they are generally sold as Class-1 laser products. This means that they comply with international safety regulations to prevent the user from coming into contact with the dangerous laser. The first line of defense is usually an interlock with the machine’s lid — the laser will not fire when the lid is open.
If this interlock is bypassed or manipulated, you risk exposure to a dangerous laser that can harm your eyes or skin.
The laser cutter’s manufacturer knows the limitations and inherent risks of their design. Each laser cutter will include certain interlocks and design features that are intended to keep users and equipment safe. Make sure to read through the safety and operating instructions after buying a new cutter. If the manufacturer has recommended limits or highlighted particular risks, it is important to take note and follow these guidelines. By ignoring them and operating outside of the manufacturer’s guidelines, you run the risk of voiding warranties, damaging equipment, and harming yourself or others.
A logbook recording what materials have been cut and by whom can be important to safe operation. Some materials may leave flammable residue behind. Also, if anything seems unusual upon inspection of the cutter, the last person to use the machine can be consulted so the new operator knows what was in the machine last. A log of the laser’s operating hours can also be important so your shop can perform periodic maintenance on schedule.
Fire is always a risk when operating a laser cutter. Some materials are more likely to catch fire than others. Since the laser, by design, melts, vaporizes, or burns material, fire is a preeminent possibility. A fire extinguisher must be clearly mounted in an easy-to-reach spot very near the laser cutter. It is equally important that access to the fire extinguisher is not blocked by clutter on the floor or by placing another machine in front of it.
6. Vacuuming the Cutting Deck and the Internal Cavity of the Laser Cutter on a Regular Basis Is Critical for Fire Prevention!
The buildup of dust within the laser cutter’s housing significantly increases the risk of a fire. Dust particles are naturally very small and therefore have a large surface-area-to-volume ratio. This allows large amounts of air (and oxygen) to be in contact with the particles at all times. As a result, dust ignites more easily than a solid block of the same material.
An initial ignition of dust can also lead to a dust explosion, where the initial reaction disturbs more particles and the flame travels through all the suspended dust. This causes a dust explosion, which can be remarkably powerful. To avoid the risk of dust igniting, you must regularly clean the inside of your laser cutter as well as the cutting deck and anywhere else where dust may concentrate. Use air assist to quickly blow away dust and smoke that could easily ignite.
Some materials are not safe to cut with a laser cutter. Usually, this is for one of two reasons: they have a high risk of causing a fire, or they release toxic fumes when struck by the laser. Take the precaution of researching each material before cutting. An example of an unsafe material is PVC plastic. When it is cut by a laser, the polymer decomposes to release hydrogen chloride gas. This forms hydrochloric acid when it encounters moisture, such as in a person’s eyes or lungs.
An operator should never leave a laser cutter unattended while it is running due to the risk of ignition. Fire is an ever-present possibility when working with high-powered lasers. The workpiece (or dust inside the machine from previous jobs) may ignite at any time during operation. If the laser cutter is supervised, quick action can immediately put out the fire — generally by using a CO2 fire extinguisher at the base of the flame.
Properly mount laser cutters on a firm, non-flammable surface such as a concrete or steel deck. Laser cutters should not be placed on wooden surfaces due to the risk of fire. Materials inside the machine may occasionally ignite, so all reasonable precautions should be taken to reduce the risk that such a fire could spread.
Laser cutters use pulsing firing patterns to increase their peak optical energy. Rather than emitting a constant power output, a pulsed laser provides short bursts at higher power levels. The laser “stores” energy between pulses, so slower pulse rates (lower frequencies) generate more energy per pulse. Conversely, a higher pulse frequency will have lower peak energy. Therefore, lower pulse frequencies run a higher risk of causing fires in the material being cut.
The most dangerous thing that a laser cutter can do if used incorrectly is cause a fire. Further, it can warp, melt, or otherwise damage your material if the settings are incorrect or if an unsuitable material has been used. If a dangerous material has been placed in the chamber, laser cutting can also release toxic fumes.
The main accident risk with a laser cutter is fire. If a material being cut combusts, it may continue to fuel a larger fire as time goes on. Additionally, some laser cutters have plastic enclosures that they can burn. This fire will not only damage the machine but could spread within the workshop and damage or destroy many other pieces of equipment.
There are a number of other health and safety risks to people working with laser cutters if the necessary precautions are not taken. Accidental exposure to the laser can easily cause permanent eye damage or burns to the skin. A further risk to operators (but usually over the longer term) is respiratory irritation due to inhalation of toxic fumes. A fire involving dangerous materials will release even more toxic fumes which may cause acute respiratory reactions.
Lasers are directly harmful to humans if they come into contact with a person’s skin or eyes. The blink reflex is too slow to block a laser’s energy before it damages the retina. The laser essentially burns a hole in the macula and causes bleeding of the retina. Depending on the laser’s wavelength, it can also affect the lens and cornea. These will all permanently affect a person’s sight.
Lasers can also burn the skin. Depending on the wavelength of the laser, they can either cause thermal burns (by heat) or photochemical burns (similar to sunburn through UV exposure). Both will cause reddening and blistering of the skin.
The most important piece of safety equipment when laser cutting is a fire extinguisher. Aside from that, an emergency stop button is a key piece of safety equipment. Most machines will have one fitted on the machine, but some workshops build in an additional electrical emergency stop that cuts power to the equipment when activated.
Finally, keep a first aid kit available and easily accessible. It should be stocked specifically for treating burns.
The safety gear that should be worn when using a laser cutter includes: laser safety glasses, a mask or respirator, and thick gloves. Laser safety glasses have specifically designed lenses that are tinted to absorb the laser’s light and prevent it from passing through to the wearer’s eyes. The glasses must be matched to the laser type (and wavelength) that you are using. They also tend to be different colors according to the wavelength they absorb: blue or green for diode lasers, gray for CO2 lasers, and light green for fiber lasers.
A respirator (a cartridge mask similar to those painters wear) is also an important piece of safety gear. Depending on the extraction systems and the material that is being cut, the operator may need additional lung protection. The cartridges should be selected to protect against vapors specific to the material being cut. Most often, those are some form of organic vapors.
Thick gloves can also be useful when handling hot material that has just been cut.
The main way to protect your lungs from fumes released by laser-cutting material is to ensure that an extraction system is installed and running. Most laser cutters have a built-in extraction system to remove fumes and dust from within the machine. It generally draws air from below the cutting bed. A secondary extraction system can also be installed in the form of a hood above the laser cutter. This will remove fumes that escape from within the machine’s enclosure.
An additional way to protect yourself from fumes is to carefully select the material that you cut. Learn ahead of time what fumes will be released when cutting each material, and do not use unsafe materials if you can avoid it. For example, PVC plastic should not be cut with a laser because it releases hydrochloric gas when it melts and decomposes.
Finally, you can also protect your lungs by wearing a respirator mask with cartridges that filter the air and absorb the fumes before you breathe them in. Choose the cartridge according to what material you will be cutting — you will usually need one for organic vapors. Select one that removes the widest range possible if you are unsure.
Yes, there are a number of laser-cutting safety programs available. It’s best to ask your machine’s manufacturer which courses fit their device. If that’s not an option or they don’t have good advice, you can usually find a local laser-cutting specialist that will be able to provide safety training for laser cutters.
Yes, the laser beams in laser cutters are dangerous. These lasers are usually classified as Class-3B or Class-4 lasers, which means that they have sufficient energy to cause permanent damage to the human eye by direct or reflected exposure (and may even cause harm through diffuse exposure in the case of Class-4 lasers). These Class-3B and Class-4 lasers can also cause burns to the skin.
This article presented laser cutting safety precautions, explained what they are, and discussed how to follow each one. To learn more about laser cutting safety precautions, contact a Xometry representative.
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