Imagine if you will: a man sits in front of his computer screen, staring into the basking blue light, meditating intently to manifest his desires into reality. He holds a small black stone in his hand, with each stroke across his desk, the images on the screen dance before him. He stops, smiles gently as he sits back in his chair, raises his arms over his head to stretch deeply, lifts his feet, then kicks off from his desk. The wheels on his chair skitter across his cluttered workshop floor, he spins mid-motion to face a shimmering enclosure containing a box. For now, the box sits dark and dormant, but he holds the key to awaken what’s within.
He opens the barrier, flips a switch, and breathes life into the resting machine. Energy whirs into its carapace as lights along its edges begin to gently glow, pulsating ever so slightly, as if taking shallow breaths before waking. The machine’s lidless eye awakens, fills the room with a familiar blue light, and stares back at the man from the darkness. The artificer’s soft smile turns to a mischievous grin as he delivers instructions for his latest creation. Shockwaves of electricity shoot through the master’s blueprints, buzzing loudly as symbols dance across the unblinking eye, processing each line as fast as its hardware will allow... what will this master summon?
This isn’t a bad Twilight Zone intro or a WarHammer tumblr fan fiction, it’s actually happening in thousands of workshops right now thanks to 3D printing! Additive manufacturing, aka 3D printing has been around since the 1980’s and works by forming physical structures layer by layer from a base material. The most common materials used in hobby printing are plastic polymers in the forms of solid filaments or liquid resins, but you can print almost anything: concrete, chocolate, even glass, so long as you have the right printer for the job.
For home hobbyists looking to dive into 3D printing, the most common printers are Fused Deposition Modeling (FDM) and Stereolithography (SLA). FDM is usually the go-to choice for novice printers, due to its affordability, ease of use, and versatility. Meanwhile, SLA printers offer stunningly detailed creations using liquid photopolymer resin and UV light. These printers are a bit more advanced and demand cautious handling of resin materials, as well as additional post processing steps to arrive at a finished product. While these 3D printing technologies can seem magical in their ability to offer remarkable opportunities for creativity and innovation, it's important to remember, all magic comes with a price.
Volatile Organic Compounds (VOCs) are microscopic chemical compounds released when plastic polymers or resins are heated or exposed to light. VOCs are produced from many actions in your daily life, from washing the dishes to mowing the lawn, the smell of fresh cut grass is an example of VOCs which are harmless. These compounds are microscopic, often lighter than air, floating throughout the room. As more and more VOCs are released, they fill the space around them, similar to how gasoline fumes fill the empty space of a gas can. These compounds are what cause the distinctive, sometimes dizzying, smells coming from your printer.
Remember, if you can smell fumes, you’re being exposed to potentially dangerous chemicals. While SLA printers emit higher quantities of VOCs due to the reaction of UV curing liquid resin, FDM printers are not innocent bystanders. Poly-Lactic Acid (PLA) based filaments are generally considered harmless, but it’s important to be aware these compounds are filling the air around your printer can have side effects if absorbed into your bloodstream. Some effects appear instantly, such as a skin rash or eye irritation, others only appearing after long term exposure, like cancerous growths. Does every filament emit brain damaging VOCs? No, but it’s best to know what’s off gassing into your workspace.
Doing your homework prior to using a new filament or resin is always preferable to F’ing around, and finding out after you’ve already exposed yourself. Checking out the polymer’s Material Safety Data Sheet (MSDS) is a great first step to protecting yourself. If you’re not familiar with how to read one, learn how here. An MSDS is straight meat and potatoes content consumption. There’s no flair, no pompous, no propaganda, just quality old school scientific data sets. Each section fits into four main categories of information:
- Materials and emergency safety information- what it is, who made it, where it was made, and if it’s hazardous.
- What to do in the event of a hazard- first aid, firefighting measures. How to handle accidental release (spills or airborne contaminants).
- How to prevent a hazard in the first place- proper handling and storage,
- Useful information- handling, storage, disposal information. Exposure controls, PPE (personal protection equipment) recommendations, physical and chemical properties, stability and reactivity, and toxicological information.
MSD sheets are generally readily available, most manufacturers have a dedicated page on their website for them, but it might take a little effort to find. Usually, a site search for MSDS will pull it up, but if you’re having trouble locating them, don’t be afraid to reach out to the company and ask! A copy should also arrive with your shipment, it’s a good practice to open the fact sheet with every shipment. The chemical names and information should match what’s printed on the bottle, contact the manufacturer if there is an inconsistency.
So, you’ve ordered your resin, and you’re looking at the MSDS, and there’s info graphics in red diamonds across the page. Time to brush up on your warning labels!
What do they mean?!?!?! These are the ones you're most likely to see on 3D printing supplies:
Corrosion- this shit can dissolve metal, and you! Don’t touch this with your bare skin, wear protective gloves and clothes. Don’t breathe it in, wear a respirator. Don’t get it in your eyes, wear goggles. This product has high DPS.
Skull and crossbones- What is acute toxicity? It’s death. Either immediate, or within 24 hours. No respawns. Use at your own risk.
Health hazard- this one is pretty broad, if you see it, read through the whole damn sheet. Suck it up, and read. Don’t be a dumbass.
- Respiratory and skin sensitization- means this can cause allergy type symptoms like a skin rash, asthma, or difficulty breathing.
- Germ cell mutagenicity- means it can cause your genes to permanently mutate, and can affect future generations. Will it be infinite healing? Probably not, honestly, it's more likely your offspring will fail to thrive. And as for your mutation, well, the outlook isn’t so great for that either, which brings us to...
- Carcinogenicity- The cancer, either causing it directly or increasing the likelihood of it occurring.
- Reproductive toxicity- means it can possibly damage your sexual function, your ability to reproduce, cause miscarriages or birth defects in unborn children. This is the kind of stuff that can shrink your balls. Also, there may be evidence of breast feeding mothers passing very low quantities of VOCs to infants through nursing, but more research is needed. (https://pubmed.ncbi.nlm.nih.gov/9183837/).
- Single target organ toxicity-single and repeated exposures- this class means a specific organ will be affected and how long of an exposure needed to affect it.
- Aspiration hazard- “Aspiration is defined as the entry of a liquid or solid into the trachea or lower respiratory system directly though (SIC) the oral or nasal cavity, or indirectly by vomiting. … Serious health effects can occur such as chemical pneumonia, injury to the lungs, and death.” -https://www.ccohs.ca/oshanswers/chemicals/whmis_ghs/hazard_classes.html
The exclamation mark is really just a catch all of the worst of the worst, and indicates you should read the whole damn sheet before you open whatever this is.
Just so you know, the Canadian Centre for Occupational Health and Safety doesn’t require a hazard pictogram for all hazard categories. Pictures are great, but make sure you read the fine print. Curious what categories aren’t labeled with bright photos? Here they are:
- Aerosols- Category 3- there's only 3 categories of aerosols. This is the most dangerous category, meaning it's super flammable, and shouldn't be used near anything with a high temperature, like fire pits, grills, or lit cigarettes. Don't light a cigarette near this stuff. That's blow yourself up behavior, Okay? Don’t get safety slack, and burn off your pretty face being a noob. You likely won't see this listed on your 3D printing supplies, per say, but you might encounter them when working with post-processing materials like paints and sealants.
- Flammable gasses- Category 2- These aren’t as likely to combust as category 1, but they’ll still show out if you give them the chance. It’s good practice to know if something in your general area is flammable and to keep that in mind when you’re working.
- Flammable liquids- Category 4- doesn’t get a picture because it requires excessive heat, or special conditions, to combust.
- Self-reactive substances and mixtures- Type G- the least hazardous in this category doesn’t mean it isn’t hazardous.
- Organic peroxides- Type G- treat all peroxides with respect, even the less dangerous ones.
- Combustible dusts- Category 1- usually organic materials such as fine particles of wood, paper, or cloth materials.
- Simple Asphyxiants- Category 1- there’s only one category. It’s usually just a warning that these are present, and to use applicable PPE. Not sure what PPE to use? Read the MSDS.
- Serious eye damage/eye irritation- Eye Irritation- Category 2B- if something you're working with is in this category, it’s on par with cutting onions. Symptoms will clear up within 7 days of exposure with no long term negative effects.
- Reproductive toxicity- Effects on or via lactation. If a nursing mom is exposed to this, there’s potential risk that it will pass to the infant when feeding.
While both FDM and SLA printers emit VOCs, the dangers of FDM printing PLA are a little more straightforward and easier to mitigate. All you have to really worry about is not burning yourself on a hot nozzle, and making sure there’s ample ventilation if you’re using a high VOC filament.
Popular filaments ranked by emissions lowest to highest:
- PLA- Polylactic Acid- the most popular filament types due to its affordability and having the lowest emissions in the filament market. It’s made from plant-based materials like cornstarch, and is considered renewable. Fun fact, if someone tells you its bio-degradable, ask them how long it takes to break down…
- PETG- Polyethylene Terephthalate Glycol- based filaments are also considered low emission, though slightly higher than PLA, it prints a sturdier product.
- TPU- Thermoplastic Polyurethane- this flexible filament does emit some dangerous VOCs, but not nearly as terrible as the more rigid plastics. Watch your temperature range with this one, as high temps can cause more off-gassing.
- Nylon- Polyamide- filament has moderate emissions of VOCs that can vary based on formulation. It’s very strong and durable.
- PC- Polycarbonate- filament emits higher levels of VOCs and may produce strong fumes that require ample ventilation.
- ABS- Acrylonitrile Butadiene Styrene- filament produces strong, durable, impact resistant prints with a high heat tolerance. This is one of the most toxic of the FDM filaments, and styrene could probably have a whole blog to itself, as the EPA can neither confirm nor deny its negative effects. Even though there was a noted increase in spontaneous abortions and a decreased frequency of live births in a study on the reproductive effects of styrene on humans. There just isn’t enough evidence to make a solid association. (https://19january2017snapshot.epa.gov/sites/production/files/2016-09/documents/styrene.pdf page 2, reproductive/developmental effects.)
SLA (Resin) printers add additional hazards because of the medium used to print. With FDM printers, the polymer filaments are already solid, and don’t require the addition of photo initiators. Photo initiators are the compounds found in liquid resin that react to light exposure. The energy they emit when excited by ultraviolet light starts a series of reactions, causing the free-floating monomers and oligomers to form into polymer chains and solidify. Unfortunately, once they’ve been excited and their bonds break, what’s left is a free radical. These highly reactive compounds are then off-gassed into your print space as a potentially DNA altering fog. Fun!
So, next time you’re about to walk into your print space with no PPE, remember you’re essentially inhaling gulp after gulp of potentially body altering chemicals, and not the fun kind. Some of these VOCs are so small, they can be absorbed into the blood upon inhalation, but others aren’t so tiny and can build up inside lung tissue over time, potentially giving users the 3D printed version of COPD with long term exposure. Your lungs aren’t the only way these guys leech in, VOCs can settle onto exposed areas of the body and be absorbed through your skin’s protective barrier, or through membranes in your eyes, nose and throat. VOCs are an unavoidable side effect of working with plastic polymers and resins, but there are ways to mitigate your exposure to them.
- Limit Exposure- Keep your printer away from your living space, if possible. Don’t spend any extra time around your printer. Get in, get the job done, leave the area. Do not print in the bathroom, while the idea of turning on the fan to suck out the VOCs might sound ideal, your counter surfaces and toilet seat will still make a fine landing place for VOCs not removed.
- Ventilation- Making sure your printer is in a well-ventilated area, preferably away from you and your family, should be your number one priority. Open a window. Use a fan to draw air outside. Build an enclosure with a ventilation system that dumps VOCs out of the house. Do what you have to do. Amazon sells “inline exhaust fans” (https://amzn.to/3wOrWR3) + (https://amzn.to/4aHChw0 ) for less than $50.00, combined with some ventilation ducting, you can plumb the fumes right outside.
- Air Filters- Using an air filtration system can help reduce emissions in your print space. If you’re 3D printing inside your home, or in a space connected to your home, it’s not a bad idea to put air purifiers in your living areas as an extra layer of protection. While VOCs are not captured by HEPA or ULPA filters and require the use of large amounts of activated carbon to be captured, pissing in the wind is still a relief.
- Respirator- Inhalation is how you are exposed to the highest amounts of VOCs when 3D printing. These microscopic particles float around in the air which means you can breathe them in. Do yourself a favor, and just buy the good one. This is the most crucial tool you’ll have to protect yourself from VOCs. 3M makes a solid option (https://amzn.to/3UZkdHM + https://amzn.to/4bFGDFb ) will have you on your path to safety.
- Cover Up- What goes up, must come down. VOCs floating through the air will eventually settle like a fine particulate dust on any surface in its path- including you. This can cause eye and skin irritation, with some people’s reactions to exposure worsening over time. It’d be a shame to invest in this hobby only to have to stop because you’ve overexposed yourself to chemicals and have a worsening allergic reaction every time you walk in your print space. Goggles, gloves, long sleeves, long pants, and full coverage shoes. Gloves: https://amzn.to/4aI6z Goggles: https://amzn.to/3Ra7vFb
3D printing is a great hobby, we’d hate to see you leave it too soon over something completely avoidable. Freedom comes with responsibility, don’t let the nannies out there stifle a revolution ‘for your safety’. Don’t F-around and find out like this guy:
***A word from Mr. Mediocre:
This article was born out our own experiences and we intend to keep it updated. I myself have become very sensitive to the VOCs emitted during resin printing. This seemingly was caused by running four Elegoo Saturn Printers in a six by ten room with no ventilation. I found myself constantly sneezing, eyes watering and unescapably itchy, skin irritations, etc… I felt like I was constantly having an allergic reaction. The inline ventilation exhaust mentioned earlier was an idea found through watching “Once in a Six Side” on YouTube (https://youtu.be/zk9KcGAH_Zc?si=zULDQ04tFh5hoIrt). I highly recommend his channel if you are new to 3D Printing.
As time as progressed, I have been lucky enough to afford a proper fume hood and appropriate ventilation for our scale of printing. This is not necessary for everyone, but for me it has managed my symptoms as I refuse to give up my passion of printing and painting miniatures. I challenge you to be safe, have fun, and never stop learning about your new found hobby!
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