Information on Laser Safety - Air Venting or Filtering

I compiled some information that I thought would potentially help others.

Even wood is unsafe to cut with a laser without proper ventilation. See https://www.cmu.edu/ehs/Guidelines/ehs-guideline---laser-cutter-safety1.pdf.

Unless you know for certain that the material you are etching/cutting is free from contaminants, even wood or MDF release unsafe chemicals. That’s because most wood products are just that, products. They aren’t just wood. There are glues and other binders as well as chemicals used to treat the wood that can and will be released into the air with a laser.

Here are the chemicals cited by the Carnegie Mellon information:

Benzene: Benzene | C6H6 - PubChem - Not safe - “Exposure to this substance causes neurological symptoms and affects the bone marrow causing aplastic anemia, excessive bleeding and damage to the immune system.”

Formaldehyde: Formaldehyde | H2CO - PubChem - Not safe - “Toxic if inhaled”

Acrolein: Acrolein | CH2CHCHO - PubChem - Not safe - “Very toxic when inhaled”

Polycyclic Aromatic Hydrocarbons - Dibenz[a,j]acridine | C21H13N - PubChem - There are many different types. This is just one of them. “Suspected of causing cancer.” “Suspected of causing genetic defects.”

Perhaps not everyone would buy into what the NIH and CM have to say about what chemicals are released and what effects they may have on the human body. But, I believe these are good sources of information. I recommend that everyone either vent to the outdoors or use an air filter such as the one offered by Snapmaker.

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Well, I don’t even use processed woods to begin with. I use trunks from dead or dying trees that have already fallen and cut them into whatever I need dimensionally, via my table saw.

As far as the Snapmaker air purifier goes… they aren’t concerned with the effects on the human body… otherwise they wouldn’t even have made the air purifier. Think about it, why make an air purifier if it still requires to vent out a window, when venting straight out the window without the purifier makes no difference to the actual user of the machine. It’s all indicating concern for public image for 3d printers in general, trying to appease a certain crowd that claims 3d printers are polluting our atmosphere. Theyre probably trying to get ahead of the curve before it actually becomes a huge problem for the industry.

If you use raw wood, then I would guess that you have nothing to worry about. The reason for my post is that I have seen multiple posts here claiming that risks of using a laser indoors is overstated. It is not. You conflate the issue by discussing 3-D Printing. My post is specifically talking about chemicals released when a laser is applied.

As far as the air purifier from Snapmaker goes, if you don’t like it or don’t need it, don’t buy it. I’m not advocating for the purchase of the Snapmaker filter specifically. I’m advocating for the use of A filter or venting outside.

That said, I think it is premature to disregard the Snapmaker air filter since it hasn’t even been put in people’s hands yet. And, unless you are accusing Snapmaker of false advertising, they clearly show the reduction in various pollutants on their page: Snapmaker 2.0 Air Purifier – Snapmaker US. I haven’t seen any information about this, but I think it remains to be seen whether it is actually required to port the output from the filter to the outdoors. There are other reasons why someone may want to still the hose going outside even if the air is filtered.

I received an email from support today after inquiring… they told me you must vent ourdoors.

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@JonnieCache the gripe has been that the air filter still requires you to vent outside according to Snapmaker, leaving absolutely zero benefits to buy it. There’s no difference for the user of the machine whether they buy the filter or not. The point of a filter would be to no longer have to vent outside, but that’s not the case. There’s nothing the filter can do that the enclosure fan cannot because the result is the same, it’s vented out of a window. Venting out a window has the same benefit to the user of the machine as the air filter. Same result just an added unnecessary step.

@Artezio I’d guess that even if their purifier functioned perfectly and removed all contaminants, they’d still “recommend” venting it to the outside. It gives them protection from liability if something goes wrong, as well as making it easier to brush off defective filters by saying that the purifier is supposed to exhaust outside anyways.

I definitely see your point that they could be making it just to boost public image, and I wouldn’t put it past them to do such a thing But it remains to be seen how effective it is, especially at the price point they are selling it at. I hope to be pleasantly surprised, but I also do not plan to ever buy one as a diy solution works for me.

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I understand the gripe, but as I mentioned above, nothing I have seen requiires the venting of the filter air outside. As @MooseJuice provides above, SM is recommending that it be vented outdoors. But, a recommendation from a manufacturer is not the same as a requirement. @MooseJuice, it doesn’t say that you “must”. Further, a statement from one representative of the company is less important than what the official documentation for the product says.

@bobby4718 is likely correct that they are saying that for liability reasons.

I just found the manual for the Air Purifier at https://s3.us-west-2.amazonaws.com/snapmaker.com/download/manual/Snapmaker2_Air+Purifier_EN_V1.0.0.pdf. It does state, “Put the unattached end of the hose outdoors.”

An important distinction here is whether the exhaust must be pumped outside because of actual safety reasons or whether they are saying that to just cover themselves. Either way is unacceptable or at least undesirable. Regardless of the truth of the matter, they may be able to avoid liability by claiming a consumer didn’t use the product as intended. I say only may because it is not a guarantee to Snapmaker that they would be able to successfully use that defense to avoid paying for an injury just because of that one sentence. There are all sorts of reasons (such as labeling, the sentence is inline with the rest of the paragraph and not highlighted) why they may still lose if someone is harmed as a result of the use of their filter completely indoors.

There are other manufacturers, such as Glowforge, that produce this type of air filtering equipment, but specifically state that it is safe to use indoors, so we know it is possible. I think this is a messaging or marketing issue for Snapmaker that they should address. At the very least, it raises questions and eyebrows and will likely hurt sales of their air purifier.

There is just a whole mis-mash of information here that does not form a coherent picture.

The fumes from CNC, laser, and 3DP are, while technically a health hazard, so small that the permissible exposure limits would be difficult to violate even with continuous operation in an enclosed room with no ventilation.

Glowforge, a high powered CO2 laser, also agrees with this, however this is unimportant and I don’t want this to distract from the below points.

However, apparently, snapmaker does not, with the comparatively puny 1.6W laser. Apparently here it’s a huge health hazard requiring not only ventilation, and no only filtration, but both filtration followed by ventilation.

The sources posted in the original post correctly identify that things are health hazards, however they do not discuss the PEL, generation rates, or expected concentrations.

Just as a single counterpoint, for the purpose of some perspective: Acrolein, the NIOSH PWL is .3ppm (.25mg/m^3), and the NIOSH listed symptoms are primarily irritation. That makes sense as acrolein is generated through the incomplete combustion of cellulosic material. By a study acrolein makes up 13% of the total aldehydes in smoke, and concentration of up to 50ppm are found in wood smoke, and as a potent lachrymatory agent is why around a campfire when the wind blows into your eyes you get watery eyes. If you are using your laser in a room that is so smokey that walking into the room causes your eyes to start watering, then the acrolein concentration is at least above 0.06ppm, from the above study, and nose irritation begins to occur at 0.15ppm. Both of these are below the PWL of 0.3ppm, and I would expect most people would not operate their laser so long in a sealed room as to be continuously exposed to nose and eye irritation. Combined with the ASHRAE recommendation that a home is built to receive 0.35 air changes per hour even a non-ventilated room will have a slow, but steady supply of fresh air limiting the maximum upper concentration.

In summary, ventilation and filtration is good, but the generation rates are so small that in even a moderate sized room the dilution will bring the concentrations down below PEL.

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I agree with you on many of your points. I think the biggest issue is that the amount of pollutants in the air caused by use of a SM cannot be known by a regular consumer. I would rather be safe than sorry. Yes, smoke from burning wood carries pollutants, but you wouldn’t light a campfire indoors and a properly working chimney will cause the smoke to be pulled outside.

For those of you interested, I have posted an open letter to SM regarding the Air Purifier: Open Letter to Snapmaker re: Air Purifier

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Certainly true for 3DP (unless you’ve got some weird filament with high vapor pressure at its melting point). Mostly true for the tiny laser, though if you’re in semi-production mode with a high duty cycle it could be a problem. For the CNC, though, I’ll differ. Wood dust is a significant hazard at level far lower than previously understood. I’d not recommend that without an enclosure or point-of-generation dust removal. Other kinds of dust are comparable, as some of the problem is simply particles of a certain size. An occasional CNC project is going to cause a big mess, though, before it’s a significant health hazard, and it provides a second (and lesser) reason to remove the dust.

The largest source of acrolein exposure many people get is not wood smoke but from charred meats, such as hamburgers from a grill or crispy bacon. Usefully, though, acrolein is quite reactive and has a short half-life. Letting meats rest for a few minutes before eating gets rid of almost all it, certainly below any PEL.

More to the point for a filter, acrolein doesn’t form hazardous waste because it degrades long before that’s an issue. There’s point in filtering it out of an outside-exhausted air stream. There’s good reason to filter it out of an indoor-recirculated one, though, since it’s still reactive exactly when being introduced into indoor air; it doesn’t last long, but it’s not preferable to be in the same room with fresh fumes.

That’s the case for acrolein. Other kinds of fumes are not nearly so immediately reactive. Aromatics like benzene and PAH, particularly their chlorinated variants, are long-lasting and don’t degrade rapidly in the environment. So it’s still a good idea to filter-or-exhaust.

I have a problem with chemical hysteria generally, and laundry-lists of Things That Might Be Bad For You promotes ignorance and fear, not rational responses to actual hazards. Acrolein is a good example of a substance that deserves something more than an it’s-there-it’s-bad attitude.

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In terms of 3DP - I don’t think quality PLA or PETG are particularly dangerous. That seems to be the consensus for the most part and my Mila air filter doesn’t seem to give two hoots about it. Funny though, if I use Chinese garbage, it starts whining about it. So you get what you pay for.

ABS, however, has more controversy behind it. During printing it fumes styrene. Some people say it is a miniscule amount and not relevant, others say even a tad is dangerous.

I don’t know what to think about this to be honest. I think that it certainly depends on the scale of your printing operation. I tried printing ABS once with the machine (which did not go too well) and I didn’t notice the infamous foul odor associated with it.

So what about this styrene? Does the air purifier effectively work against styrene?

I think I can buy the idea that the air purifier device needs some “legal leeway” in their installation recommendations.

However, perhaps if we had facts about how well it does performance wise against byproducts of machine use such styrene or fumes from various laser products, as opposed to just being a filter in place that still requires outdoor exhaust with no real explanation to what it actually is accomplishing, it would make more sense for us to be able to make the determination as to whether or not we feel the investment is worth making.

I really want to like this device, and want to give the benefit of the doubt on the “legal leeway theory” because it makes a lot of sense, but not having any facts to go off of, that’s difficult to accomplish.

I was ignored on this point when I raised it on the other thread.

They marketing material, amongst other things, lists nitrogen oxides:

Their filter, as I understand it, cannot remove nitrogen oxides as it’s not a particulate or a VOC that would react with the activated carbon filter.

Another chemical listed is HF, which requires organic vapor/acid gas active filters.

After publishing such a list of hazards, to avoid it seeming unnecessarily alarmist, I would expect Snapmaker would be publishing removal rates and efficiency of those emissions.

Since Snapmaker has said the effluent should be directed outside, presumably because the chemicals listed in their marketing material cannot all be filtered, I’m not sure where that leaves this as a product.

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I just noticed this footnote on the air purifier pre-order page:
image

Essentially directing you to turn it off for ABS, but then filter for a bit before opening the enclosure.

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This must relate to the air flow causing the material to warp from cooling quickly. That makes sense but also doesn’t help the cause here on wanting to purchase it.

If the air system is offline, that means the fumes will escape from the gaps in the enclosure. Perhaps not enough to matter… but thats certainly a hard pill to swollow.

So heres a question, can we control the air purifier with Gcode like a standard extra fan? To add a routine at end of print to run the fan for a duration? Maybe we can even control the flow rate? Control over the purification process via gcode could be something interesting to have.

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GCODE control would be nice for sure.

Can I just say that I’m SO annoyed that we even have to be having this discussion? If I didn’t like Snapmaker products, I would have given up a long time ago. C’mon @Melitta_Snapmaker @Snapmaker-Support… what’s the point in having a forum and Admin accounts if you aren’t going to actively participate?

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M1011 is the control command

/*purifier control and data capture
* F[0-3]: set fan gears
* D[0-65535]: fan delay close time. unit S
* P[0-255]: set fan power(debug)
* R-G-B-[0-255]: set light color. eg. R100 G20 B30 (debug)
*/
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There’s also @staff which has some people but not the guy responding on the purifier post. Very weird.

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@eh9: For the CNC, though, I’ll differ. Wood dust is a significant hazard at level far lower than previously understood.

I agree with you that it can be harmful. I never intended to say or imply that 3DP or CNC is safe without a filter. I was just intending to address some misinformation that I have seen elsewhere regarding laser safety.

@eh9: I have a problem with chemical hysteria generally, and laundry-lists of Things That Might Be Bad For You promotes ignorance and fear, not rational responses to actual hazards. Acrolein is a good example of a substance that deserves something more than an it’s-there-it’s-bad attitude.

I’m not meaning to induce hysteria. If it came across that way, I apologize. Obviously, some chemicals are worse than others for one’s health. The problem I see is that the given chemicals released during Laser, CNC, 3DP is an unknowable for consumers. All the different types of materials, even varying by manufacturer, could release different chemicals.

Since the consumer can’t know what’s good, bad, really bad, seriously bad, deadly, we deserve a filter that will allow these machines to operate safely indoors. And by safely, I don’t mean totally devoid of any chemicals–I mean reducing any type of harmful chemical to a level that is safe for human exposure.

Do I want to harm the environment? Of course not. But, I also don’t know, especially given the low volume that I intend to use my machine at, that I want to pay $500 for the filter and $100 per replacement cartridge.

I’m not advocating for governmental regulation by saying this. But, I think there is a lot of misinformation, misleading information, missing information in this “maker” space as a whole on what is safe to do without filtering and what requires a filter. I think as consumers, we need to hold companies accountable. But, as others have said, perhaps Snapmaker doesn’t give a care. I hope that’s not the case. I plan to contact more people in the media in the hopes that we can get answers.

Oh no. Can’t wait to read about “is your child’s 3D printer giving you cancer?”

Maybe Carnegie Mellon or some other research institute, or OSHA or NIOSH would have information.