This document covers some basic safety information on the processes of laser engraving.
DISCLAIMER: Laser Engravers emit deadly high voltage and laser radiation capable of causing instant blindness and tissue damage. Lasers are a fire hazard. Keep extinguishers close and NEVER leave the machine unattended. The lasing process causes dangerous, and sometimes deadly, smoke and gasses that will kill you and literally ruin your machine!
Thunder Laser procedures and guidelines always supersede this documentation. Always follow all safety recommendations and MSDS data. By accessing this document you acknowledge that you have read and understood, in their entirety, and agree to our Terms & Conditions.
THIS DOCUMENT COVERS MEDIUM INFRARED ~10.6μm CLASS 4 CO2 LASERS ONLY
NEVER LEAVE YOUR LASER RUNNING UNINTENDED
Fully enclosed and interlocked laser cutters are normally low-risk, Class 1 lasers in accordance with ANSI Z136.1 Safe Use of Lasers. These devices are safe when used as designed, without manipulating the safety features, and are exempt from UW laser registration and other control measures. The red dot pointer is included in this class.
HOWEVER, the lasers embedded inside the enclosed system are often Class 3B or Class 4 lasers, which emit high energy laser beams capable of causing serious eye and skin injury if the beam is not contained within the device. Therefore, safety interlocks should never be bypassed. We also offer a certified Class 1 laser via special order.
THUNDER LASER MACHINES ARE COMPLETELY SAFE TO OPERATE AS LONG AS ALL DOORS ARE CLOSED AND ALL SAFETY SYSTEMS ARE IN GOOD WORKING ORDER.
C02 Laser Radiation
Moderate and high-power lasers are potentially hazardous because they can burn the retina of the eye or even the skin. To control the risk of injury, various specifications like 21 Code of Federal Regulations (CFR) Part 1040 define "classes" of lasers depending on their power and wavelength. These regulations impose upon manufacturers required safety measures, such as labeling lasers with specific warnings, and wearing laser safety goggles when operating lasers.
Thermal effects are the predominant cause of laser radiation injury, but photo-chemical effects can also be of concern for specific wavelengths of laser radiation. Even moderately powered lasers can cause injury to the eye. High power lasers can also burn the skin. Some lasers are so powerful that even the diffuse reflection from a surface can be hazardous to the eye.
The coherence and low divergence angle of laser light, aided by focusing from the lens of an eye, can cause laser radiation to be concentrated into an extremely small spot on the retina. A transient increase of only 10 °C can destroy retinal photo-receptor cells. If the laser is sufficiently powerful, permanent damage can occur within a fraction of a second, literally faster than the blink of an eye. Exposure to laser radiation are largely absorbed by the cornea and lens, leading to the development of cataracts or burn injuries.
Infrared lasers are particularly hazardous, since the body's protective glare aversion response, also referred to as the "blink reflex," is triggered only by visible light. People exposed to invisible laser radiation may not feel pain or notice immediate damage to their eyesight. A pop or click noise emanating from the eyeball may be the only indication that retinal damage has occurred i.e. the retina was heated to over 100 °C resulting in localized explosive boiling accompanied by the immediate creation of a permanent blind spot.
Lasers can cause damage to biological tissues, both to the eye and to the skin, due to several mechanisms. Thermal damage, or burn, occurs when tissues are heated to the point where denaturation of proteins occurs. Another mechanism is photo-chemical damage, where light triggers chemical reactions in tissue. Photo-chemical damage occurs over the course of hours. Laser pulses shorter than about 1 μs can cause a rapid rise in temperature, resulting in explosive boiling of water. The shock wave from the explosion can subsequently cause damage relatively far away from the point of impact. Ultrashort pulses can also exhibit self-focusing in the transparent parts of the eye, leading to an increase of the damage potential compared to longer pulses with the same energy.
Personal Protective Gear
Users need to be properly trained on the potential hazards, control measures, lab and manufacturer’s operating procedures, use of personal protective equipment (PPE), emergency procedures, and safety precautions for operating the engraver. The required PPE includes safety glasses to protect eyes from radiations, particles, debris, etc., proper skin protection to reduce burns, and hearing protection (if necessary).
The glass laser safety viewing windows installed in Thunder Lasers, in combination with safety interlocks, do provide adequate protection and conform to published safety standards.
Eye protection suitable to the laser should be worn within the laser control area if there is a potential for exceeding the MPE limit if the beam is viewed or if you are operating the unit with the safety interlocks defeated for maintenance, adjustment, etc... Protective eye wear may include goggles, face shields, spectacles or prescription eye wear using special filter materials or reflective coatings.
You want to look for a CE certified solution that specs the 10,600nm (10.6μm) wavelength and an Optical Density of at least 6+.
ALWAYS keep a properly maintained and inspected fire extinguisher on hand. Thunder recommends a carbon dioxide fire extinguisher or a Halotron extinguisher. You can use a standard multi-purpose dry-chemical fire extinguisher but they leave a sticky, corrosive residue that is very difficult to clean up and it can damage the electronics. The CO2 extinguisher leaves no residue at all. The Halotron extinguisher emits a clean, easily removable substance that is not harmful to the mechanics or wiring of the laser system.
Here is a link to a CO2 extinguisher for reference:
Here is a link to a Halotron extinguisher for reference: