Laser classes are used to indicate the safety level of lasers. Before 2002, lasers were broadly classified into four categories. Due to the vague definitions of Class 2A laser and Class 3A laser in the old system—which were prone to confusion with other classes.
For instance, the standard for Class 2A laser was "safe only if viewed for no more than 1000 seconds per day," a rule that was overly ambiguous, making it difficult to implement. After the 2002's revision, laser types were further refined, leading to the introduction of Class 1M, 2M, and 3R lasers.
It's important to understand the laser class you're working with, whether using laser pointers or desktop laser engravers, to ensure the safety of yourself and others.
Basics of Laser Classes
Sheet below is for understanding differences among laser classes, which shows its main features and risks:
What is class 1 laser?
Class 1 Laser
IEC 60825-1: Safety of laser products – Part 1: Equipment classification and requirementsIEC: International Electrotechnical Commission
Class 1M Laser
What is class 2 laser?
Class 2 Laser
Class 2 lasers emit visible light. They're safe as long as you don't stare directly into the beam. Your eyes have a natural reflex that makes you blink quickly when exposed to bright light, which helps protect you from brief exposures. Common examples include laser pointers and laser levels.
Class 2M Laser
Class 2M lasers are similar to Class 2 lasers — but they can become dangerous if viewed with optical tools like magnifying lenses. So remember: keep those magnifiers away from the beam!
Red one is example for class 2 laser
Common Applications and Examples
• Laser pointers: Used in presentations and for pointing.
• Laser levels: Applied in leveling and alignment tasks.
• Light curtains: Provide safety protection in various equipment.
• Laser projectors: Employed in laser shows and exhibition displays.
Safety Tips for Class 2 & 2M Lasers
Never look directly into the beam of Class 2 or higher lasers — and remember that reflected beams can also be harmful to the eyes. Never aim a laser at airplanes or vehicles. Even low-power beams can cause glare or temporary vision loss.
A Class 2 laser with a power of 0.99 mW can have a Nominal Ocular Hazard Distance (NOHD) of up to 14 meters (46 feet) under tightly focused conditions.
While Class 2 and 2M lasers are generally safe under normal use, always handle them with caution. According to Wikipedia, accidental exposure usually doesn't cause harm — but intentionally staring into the beam can still lead to eye injury.
What is class 3 laser?
Class 3R Laser
Class 3R lasers are stronger than Class 2 and should be used with caution. For continuous visible lasers, the power can reach up to 5 mW. A quick accidental glance is usually safe since the eyes react quickly, but staring at the beam for too long can cause real damage.
Types of Risks and Explanations
• Eye injury: The longer the exposure, the higher the risk.
• Glare & flash blindness: Can cause temporary vision loss, especially dangerous for drivers and pilots.
• Dazzling effect: May distract or interfere with vehicle or aircraft operators.
Safety Notes
Never point a Class 3R laser at cars or airplanes! A flash shorter than a quarter of a second is usually safe, but staring at the beam for too long can damage your eyes.
Class 3B Laser
Class 3B lasers have higher power and can burn the eyes or skin. They are often used in laser shows and research labs. The energy is strong enough to heat tissue and cause injury. Some handheld Class 3B laser pointers can even burn the retina, though diffuse reflections—like those off paper or other non-shiny surfaces—are harmless.
Legal Restrictions and Notes
- Pointing a laser at an airplane is a federal crime and can lead to up to five years in prison and a $250,000 fine.
- Aiming at vehicles is also illegal and can result in arrest or jail time.
- Public laser demonstrations require FDA approval.
Safety Notes
Misuse can cause burns and permanent injuries. Green laser pointers are especially known for heat-related eye damage. Always follow the law and safety rules—never use a Class 3B laser in public without proper authorization.
What is class 4 laser?
Class 4 Laser
Class 4 lasers are the most dangerous type. They’re commonly used for cutting, welding, and medical procedures. These lasers can cause severe damage to the eyes and skin, and they can even start fires. Proper safety goggles are a must, and all safety rules need to be strictly followed.
Applications and Uses
• Industrial: Cutting, welding, laser cleaning
• Medical: Precision treatments, surgical operations
Class 4 Laser Safety Rules
Always wear protective goggles, avoid both direct beams and reflections, and keep flammable materials away from the laser path.
How to Identify Laser Classes
Check the product label and the user manual.
The easiest way to confirm a laser’s class is to check the label or read the manual. Manufacturers are required to follow IEC and U.S. FDA CDRH regulations, so the labels include key safety details like the laser type, wavelength, output power, and class.
Laser classes may be shown with numbers (such as 2 or 3B) or Roman numerals (such as II or IIIa). These labels are usually found on the device itself, the packaging, or in the manual.
Watch for warnings like “LASER RADIATION – DO NOT STARE INTO BEAM” or “CLASS II LASER PRODUCT”. They’re there to remind you how to use the device safely.
Example: Desktop Laser Marking Machines
Laser technology has made its way into desktop-sized equipment, but that doesn’t mean it’s completely safe to operate. All desktop laser devices are Class 4 lasers. However, thanks to the widespread use of integrated protective covers, safety has improved significantly. Even so, it’s crucial to know the laser class before use.
For instance, the labels and user manuals of the EM-Smart laser marking machine clearly indicate its classification with warnings like:
“CLASS IV LASER PRODUCT” and “AVOID DIRECT EYE EXPOSURE.”
Is it safe to use a laser engraver at home?
Yes, machines that are available on the market have passed relevant safety regulations. All desktop laser marking machine suppliers provide free laser safety glasses with their equipment — this is the most basic protective measure. Next comes the laser safety enclosure. These enclosures don’t just protect your eyes from laser exposure; they also significantly reduce the inhalation of fumes generated during engraving. That said, to maximize protection, an air filter or fume extractor should be used.
Some user guides may suggest wearing gloves during operation. While this isn’t always necessary, you should never place your hands inside the working area while the laser is active. Always remember the golden rule: stop the machine first before inspecting or adjusting anything.
Also, when engraving flammable materials like wood, never leave the machine unattended for extended periods. Whether it’s fiber lasers, blue diode lasers, or CO₂ lasers, they all use thermal processes that generate heat — which can sometimes cause materials to catch fire. So always keep an eye on the machine while it’s running.
The most important safety measure, though, is your own awareness. Always follow standard procedures and avoid any non-standard operations.
FAQs for Laser Classes
1. What if the laser class isn’t labeled on the machine?
Check the user manual or operation guide that came with your machine. If it’s not mentioned there either, contact the supplier directly. It’s always a good idea to confirm the laser type before making a purchase.
2. What class is a CO₂ laser?
Since most desktop laser engravers operate above 500 mW — whether CO₂ or other types — they generally fall into Class 4.
3. What do the letters after the laser class mean?
The suffix letters (like M, R, B, A) help define specific risks or usage conditions:
- M (Magnifier): Safe for the naked eye, but risky when viewed through optical devices like magnifiers or telescopes (e.g., Class 1M, 2M).
- R (Reduced risk): Less hazardous than Class 3B, but still not safe for direct beam exposure (e.g., Class 3R).
- B: Part of the class naming convention. Class 3B is more dangerous than 3R and can cause eye or skin burns — it’s considered high-risk.
- A: A subclass used in the older system (e.g., Class 2A, meaning “safe for average viewing time”). This category was phased out due to its complex and unclear definition.
