Safety First!

Disclaimer: I am a hobbyist, not an expert, so please seek out professionals for further advice.

Eye safety, air quality safety, fire safety, material safety, all need to be addressed when you begin to think about buying a laser. Oops? Okay, you bought the laser first not realizing there is more too it. That is Okay. You can still permantently correct or mitigate any issues now.

Eye Safety

Eye protection is super important when it comes to lasers. The simplest laser tools for hanging art require eye protection, and it is more important in our case because of reflective laser wavelengths. Eye protection is not as easy as putting on a pair of sunglasses either. You need to protect yourself from the specific laser beam wavelength. Exposure to laser wavelengths can cause temporary flashes or permanent damage to your eyes, leading to blurred vision, dark spots (I have those now from not practicing good safety), floaters, headaches, blindness in some cases, and severe retinal burn. Sounds nasty? Well, yes, because this is serious stuff.

With all of that, one might ask, is laser burning even safe? The answer is "Yes", when you apply the proper precautions, use common sense, and are aware of your surroundings and any cause and effect that could take place in the environment when operating.

Some data for you to know: (Consult equipment manufactures specifications for your exact equipment. The information here is to be considered reference only and is for the equipment I operate.)

Wavelengths (typical): 4350, 1064, and 10600 nm

ACMER S1 6W Blue Diode Laser Wavelength: 445 +5nm

ACMER P3 2-in-1 10W Blue Diode Laser Wavelength: 455 +/- 5nm

ACMER P3 2-in-1 2W Infrared (IR) Wavelength: 1064 +/- 1nm

ACMER P3 48/24W Laser Wavelength: 440 +/- 5nm

CAUTION: Do not trust the color of your eye protection will protect you from certain wavelengths. Though there is some correlation, it is never a total fact. Buy certified eye protection.

Given the Caution above, this is what industry is still saying:

Red and Orange Lens Eye Protection Good For (in general): Diode Lasers 405, 4435, 450nm and IR

Green Lens Eye Protection Good For (in general): UV, Violet, Blue Lasers, Specific IR (980 and 1064nm) depending upon shade of green

Dark Purple / Brown Lens Eye Protection Good For (in general): Filtering yellow visible light lasers

Clear Lens Eye Protection Good For (in general): CO2 Lasers

CAUTION:  The wavelength protection needs to match your laser's specific output wavelength. Some eye protection can cover a range of wavelengths.

IMPORTANT: Optical Density (OD), the higher the number the more attenuation (blocking power) the eye protection will have. The OD is dependent on laser power (wattage), e.g. a 6W laser will require a 4+ OD, whereas a 48W laser will require higher, say 6+ OD. It is okay to select a higher number, perhaps even recommended by some. Never go below the minimum requirement.

WARNING! I do not rely on the green laser glasses that came with my ACMER S1 6W because they were not marked with the wavelength rating nor the OD protection. I recommend purchasing certified glasses specifically rated for your laser wavelength, and laser wattage for improved safety. The rating of the glasses should be marked on the glasses as confirmation. No markings, no wear.

Air Quality Safety

Exhaust laser burning smoke and fumes outside. Laser burning, burning incense, campfires, basically smoke from burning anything is harmful to your health. It is likely everyone who breathes in smoke can have long term effects leading toward damage to their respiratory system, eyes, and heart. The severity will vary depending on amount of exposure and your general health at the time. Do not take this lightly and think you are superman, or can obtain “health resistance” by some method. You cannot.

You cannot hide from everything either. We do accept some risk during our daily lives. Short term low level you might choose to accept. Short term high level maybe not. This is the process of decisions we make every day, consciously or subconsciously.

What you can do is to mitigate. I will write it again, mitigate. In the case of laser burning, ventilate well, scrub the smoke out through a filter. This should be your priority, not only for your own and other people’s health, but it may help you decide where to locate (or relocate) your equipment as well.

DANGER: Some substrate materials will emit toxic fumes that most smoke eaters cannot scrub out. Research your materials and find out. Not properly evacuating toxic fumes is hazardous to your health.

The photo below is a glimpse of my ducting smoke and fumes to the outside of my garage. On the right is my P3, and on the left my S1. The company I use to obtain my Y-connector, gates, elbows from is Lakeshore3D out of Muskegon, MI. They have a great line of product, and I have experienced great service as well. Contact information at the bottom of this blog.

Fire Safety

Where there is a perceived or real fire, shut the equipment off immediately through some kind of cutoff switch. Typically, this is an Emergency Stop (E-Stop or Estop) button. For machines not equipped with this feature, quickly find and pull the plug from the power source.

The photo below is my control box for power on/off for the entire work table, and an emergency stop button. My ACMER P3 has an emergency stop, however my ACMER S1 does not. Both are powered from the same power strip that gets it's power from this control box. A word of Caution, do not use the Estop as your normal method of shutting down the electricity. Use the normal power on / off buttons. Estop will completely cut power and could cause damage to electronics, whereas going through the normal power off will allow the equipment to shut down as the engineers of the equipment intended.

Always have an exit strategy. You may find out very quick that you are not able to put out or control the fire yourself. Quickly and safely exit away from the fire and call the Fire Department.

WARNING: Whether you are a hobbyist of one, or a shop of many, visitors do come by. Make sure visitors are aware of Safety, are given the proper Personal Protective Equipment (PPE), and are informed what to do in an emergency

Never leave laser equipment unattended and have a fire extinguisher ready. The fire extinguisher shall be readily accessible, visible, and located along normal paths of travel. Near door exits is common. Where possible, place the fire extinguisher near the laser equipment, and if that cannot be done, within a maximum 75 feet travel distance for Class A hazards (wood, paper, furniture).

CAUTION: When locating near the laser, do so such that a flaming laser will not hinder or prevent your access to the fire extinguisher.

Fire Extinguisher Type

CO2 fire extinguisher is highly recommended over the ABC powder extinguisher.  It will not leave residue on the laser optics. I actually have a BC fire extinguisher located at the door connecting the garage to the house, so that if I have to use it, it the BC will be easier to clean up.

Fire Blanket

A fire blanket can be used as a secondary means for small fires. It should be kept at arms reach, and again in a location that a laser fire would not hinder you from grabbing it. I have yet to buy mine but intend to.

Material Awareness

Material Awareness may not be the first thing that comes to mind for safety. Some materials will release a toxic gas. Those materials should be avoided. Research each material’s safety, how to properly use and dispose of, and what PPE may be required. Some materials to avoid are: PVC, ABS, Fiberglass. I have a link at the bottom to ChalkWatts for a YouTube crash course on the topic.

Side Notes

The ACMER S1 does not come with an enclosure for eye protection or containment of smoke. I bought the Mini Enclosure and hang it out of the way when not in use.

For my smoke extraction I replaced the outlet to my ACMER P3 with a tight 4" 90 degree and connect it to my Y-splitter with attached air doors using a 4" flexible duct. My ACMER S1 is connected to the other side of the Y-splitter. When I run both machines at the same time both air doors are full open. If running just one ACMER laser, I shut the air door to the other machine to obtain maximum air draw. I have a magnetic quick disconnect at the exit of my exhaust fan to separate the 4" flexible duct, so that I can store my equipment. (More on that later in another blog I have to write.) The duct is quick connected to a dryer vent that goes through the garage wall, and exits where there is little pedestrian traffic and little if any affect on my neighbors.

What I enjoy is the safety of my ACMER P3. Having the laser in an enclosure to capture and properly evacuate the smoke and fumes is a huge plus. Is it 100%, no, but far better than an open system. (My additional blower in my air evacuation system helps a lot.)

The ACMER P3 also has flame detection, and alarms when a flame is sensed. One recommendation I would make to ACMER, turn off the fans when an alarm is triggered. I have failed twice to remove Post-It notes on wood I was cutting (notes were on the back side and I did not see them). They caught fire, dropped, and set the cuttings on the honeycomb on fire. The fan drew fresh air in. Air movement has a direct relationship to the intensity of a fire and how the fire behaves. The fire was actually getting bigger with the fan on. I activated the Estop, the fan stopped, which allowed the flames to dissipate. 

You really cannot put a price tag on your personal safety, the safety of your family, or safety of others near the environment. Be cautions, and most of all observant of what could be a safety problem. Correct what you find so that it does not happen, or at least mitigate to reduce the chances of happening.

Suggested Resources

Laser Safety Glasses - FreeMascot 

Dangerous vs. Safe Laser Materials (Crash Course) - ChalkWatts

Exhaust Components - Lakeshore3D

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