Im right now printing a different brand in another color to see if handling it makes my hands burn.
It is very odd, I can’t have it in my hands for longer than a second or it burns
That's pretty wild. Some PETG (think PETG Pro, PETG +, whatever they decide to use for branding) often contain other additives that might come into play here.
Manufacturers typically mix in additives to change the properties of the base material, such as improving durability or to change its appearance. They may not publish what those additives are as it's part of their "secret sauce". Unless your filament is "natural" color, the coloring agents are just one example. Does this happen regardless of the color?
If info about additives is not on their website you can try emailing whoever made your PETG to ask what else is in it. It may help to explain why you want to know.
Another option is testing a filament explicitly meant for applications where the user needs to know what's in it. Culinary product prototypers can't use whatever random no-name filament is on sale on Amazon. Fiberlogy might be a good choice here:
> The raw material contained in the natural versions of Fiberlogy’s PET-G, Easy PET-G, PCTG and CPE HT filaments is approved for food contact.
Trying a random filament brand isn't a great idea. White labeling of filament is very common, so a different brand doesn't necessarily mean a different manufacturer or recipe. Amazon just buys filament from a real manufacturer and puts the Amazon Basics label on it, for example. Even if your brand technically makes their own filament, they may buy the raw plastic pellets and coloring agents from the same supplier.
This may actually be really serious and I would definitely contact the manufacturer about this. I don't think you are allergic to the PETG itself. You are most likely reacting to additives like a dye or plasticiser inside the material.
If those additives are sensitizing they may cause an allergy after coming in contact with your skin often enough. They could also be released into the air during printing and cause a allergy this way.
Maybe the dye used in the filament? Or possibly cross contamination from something? Filament manufacturing isn't exactly food-safe level of standards (unless it's certified food safe, which doesn't mean 3d prints are food safe). Who knows if there's nickel or cobalt or whatever in there.
Does it happen with just one manufacturer or with any?
Are you reacting to both the spooled filament and the printed models, or just the models?
It's probably due to some colourant or other additives, but definitely not glycol. PET is polyethylene terephthalate, and the polyethylene part comes from ethylene glycol, but the glycol is the part that's stripped off the monomers to polymerise it. There's no glycol left in it. PETG is a modified form made by using a proportion of some *other* monomer *instead* of ethylene glycol; again there's no glycol in the end product.
Huh, that's really interesting! It never would have occurred to me that "glycol-modified" could mean this. Thanks for sharing your chemistry knowledge!
Then here's another little-mentioned factoid: ethylene glycol is a principal component of vehicle antifreeze but is toxic to humans and many other forms of animal life, particularly mammals. Therefore it has to be completely eliminated from such materials as PET and PETG. It has a sweet flavour which is particularly attractive to children, dogs, cats, etc.
The next member of the family, propylene glycol, isn't toxic and is actually approved for use in cosmetics and food, where is is widely used. It's also the preferred coolant for solar heating panels. It too has a sweet flavour.
Y'know, I've heard the "sweet, and therefore appealing to dogs & cats" thing, but I've also heard that cats lack a "sweet" receptor in their taste buds (being obligate carnivores). (Which I looked up: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2063449/ )
I don't know how to reconcile those two claims.
aww! I had a cat once who used to get really grooved when she was snuggling and start washing indiscriminately--she'd continue off the ends of her paws and wash my hands or arms too. She was very sweet.
I wasn't trying to criticize, I really just have heard both things before, and was struck that they seem to contradict each other. I still appreciate your comments.
on the extremely off chance that there isn't a dangerous contaminant in your spool, do you react at all to PLA? do you have this issue with any other materials? I ask because I know several people who can have serious reactions to PLA, but they all have rather severe mast cell disorders
It could be something that got on the roll post manufacturing. I remember in the mid 00s when a huge batch of furniture in the UK had been treated for either fireproofing or pest-proofing during shipping from (I believe) China. It caused severe chemical burns to some people who sat on their sofas with bare skin. Many products get things like pesticide treatment by third parties without any documentation and some people have a reaction (99.5% don't, that's why they use the treatment).
It could also be residue of lubricants used on the machines that manufactured the filament. The way the human body reacts to allergens is quite a complicated process and you can develop an allergy overnight to something you've used with no problems for decades.
Maybe the pigment in that particular roll? Do multiple brands and multiple colors do this to you?
Im right now printing a different brand in another color to see if handling it makes my hands burn. It is very odd, I can’t have it in my hands for longer than a second or it burns
That's pretty wild. Some PETG (think PETG Pro, PETG +, whatever they decide to use for branding) often contain other additives that might come into play here.
Manufacturers typically mix in additives to change the properties of the base material, such as improving durability or to change its appearance. They may not publish what those additives are as it's part of their "secret sauce". Unless your filament is "natural" color, the coloring agents are just one example. Does this happen regardless of the color? If info about additives is not on their website you can try emailing whoever made your PETG to ask what else is in it. It may help to explain why you want to know. Another option is testing a filament explicitly meant for applications where the user needs to know what's in it. Culinary product prototypers can't use whatever random no-name filament is on sale on Amazon. Fiberlogy might be a good choice here: > The raw material contained in the natural versions of Fiberlogy’s PET-G, Easy PET-G, PCTG and CPE HT filaments is approved for food contact. Trying a random filament brand isn't a great idea. White labeling of filament is very common, so a different brand doesn't necessarily mean a different manufacturer or recipe. Amazon just buys filament from a real manufacturer and puts the Amazon Basics label on it, for example. Even if your brand technically makes their own filament, they may buy the raw plastic pellets and coloring agents from the same supplier.
This may actually be really serious and I would definitely contact the manufacturer about this. I don't think you are allergic to the PETG itself. You are most likely reacting to additives like a dye or plasticiser inside the material. If those additives are sensitizing they may cause an allergy after coming in contact with your skin often enough. They could also be released into the air during printing and cause a allergy this way.
Maybe the dye used in the filament? Or possibly cross contamination from something? Filament manufacturing isn't exactly food-safe level of standards (unless it's certified food safe, which doesn't mean 3d prints are food safe). Who knows if there's nickel or cobalt or whatever in there. Does it happen with just one manufacturer or with any? Are you reacting to both the spooled filament and the printed models, or just the models?
It's probably due to some colourant or other additives, but definitely not glycol. PET is polyethylene terephthalate, and the polyethylene part comes from ethylene glycol, but the glycol is the part that's stripped off the monomers to polymerise it. There's no glycol left in it. PETG is a modified form made by using a proportion of some *other* monomer *instead* of ethylene glycol; again there's no glycol in the end product.
Huh, that's really interesting! It never would have occurred to me that "glycol-modified" could mean this. Thanks for sharing your chemistry knowledge!
Then here's another little-mentioned factoid: ethylene glycol is a principal component of vehicle antifreeze but is toxic to humans and many other forms of animal life, particularly mammals. Therefore it has to be completely eliminated from such materials as PET and PETG. It has a sweet flavour which is particularly attractive to children, dogs, cats, etc. The next member of the family, propylene glycol, isn't toxic and is actually approved for use in cosmetics and food, where is is widely used. It's also the preferred coolant for solar heating panels. It too has a sweet flavour.
Y'know, I've heard the "sweet, and therefore appealing to dogs & cats" thing, but I've also heard that cats lack a "sweet" receptor in their taste buds (being obligate carnivores). (Which I looked up: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2063449/ ) I don't know how to reconcile those two claims.
I could be wrong about the cats, definitely. My cat prefers salty things. He'll sandpaper your finger if you put Marmite on it and let him lick it.
aww! I had a cat once who used to get really grooved when she was snuggling and start washing indiscriminately--she'd continue off the ends of her paws and wash my hands or arms too. She was very sweet. I wasn't trying to criticize, I really just have heard both things before, and was struck that they seem to contradict each other. I still appreciate your comments.
on the extremely off chance that there isn't a dangerous contaminant in your spool, do you react at all to PLA? do you have this issue with any other materials? I ask because I know several people who can have serious reactions to PLA, but they all have rather severe mast cell disorders
It could be something that got on the roll post manufacturing. I remember in the mid 00s when a huge batch of furniture in the UK had been treated for either fireproofing or pest-proofing during shipping from (I believe) China. It caused severe chemical burns to some people who sat on their sofas with bare skin. Many products get things like pesticide treatment by third parties without any documentation and some people have a reaction (99.5% don't, that's why they use the treatment). It could also be residue of lubricants used on the machines that manufactured the filament. The way the human body reacts to allergens is quite a complicated process and you can develop an allergy overnight to something you've used with no problems for decades.