Could carbon fiber inflict the same kind of damage on the human body as asbestos? That’s the question which [Nathan] found himself struggling with after taking a look at carbon fiber-reinforced filament under a microscope, revealing a sight that brings to mind fibrous asbestos samples. Considering the absolutely horrifying impact that asbestos exposure can have, this is a totally pertinent question to ask. Fortunately, scientific studies have already been performed on this topic.
While [Nathan] demonstrated that the small lengths of carbon fiber (CF) contained in some FDM filaments love to get stuck in your skin and remain there even after washing one’s hands repeatedly, the aspect that makes asbestos such a hazard is that the mineral fibers are easily respirable due to their size. It is this property which allows asbestos fibers to nestle deep inside the lungs, where they pierce cell membranes and cause sustained inflammation, DNA damage and all too often lung cancer or worse.
Clearly, the 0.5 to 1 mm sized CF strands in FDM filaments aren’t easily inhaled, but as described by [Jing Wang] and colleagues in a 2017 Journal of Nanobiotechnology paper, CF can easily shatter into smaller, sharper fragments through mechanical operations (cutting, sanding, etc.) which can be respirable. It is thus damaged carbon fiber, whether from CF reinforced thermal polymers or other CF-containing materials, that poses a potential health risk. This is not unlike asbestos — which when stable in-situ poses no risk, but can create respirable clouds of fibers when disturbed. When handling CF-containing materials, especially for processing, wearing an effective respirator (at least N95/P2) that is rated for filtering out asbestos fibers would thus seem to be a wise precaution.
The treacherous aspect of asbestos and kin is that diseases like lung cancer and mesothelioma are not immediately noticeable after exposure, but can take decades to develop. In the case of mesothelioma, this can be between 15 and 30 years after exposure, so protecting yourself today with a good respirator is the only way you can be relatively certain that you will not be cursing your overconfident young self by that time.
Rats!
Now I need to cancel my order for the Koenigsegg!
It’s not clear if CF can be a carcinogen like asbestos. But other materials are problematic even though they don’t cause cancer. Silicosis is a very serious complication on construction and industrial sites, and can be avoided by wearing a proper respirator. You should be wearing gloves and masks when handling CF. Or when sanding *anything*: wood, plastic, fibreglass, epoxy, CF, anything. Or using any kind of aerosol paint and most solvents.
Yeah but if it’s like asbesthos that takes it out of the normal “wear PPE” realm. Maybe we should study it before it works its way into everything
The problem with asbestos is it gets into your lungs and stays there, while other contaminates eventually work their way back out.
As a bonus it’s really sharp (especially the blue stuff) to the point of causing DNA damage.
I can see carbon fibre behaving in a similar way.
In australia there is now a ban on engineered stone.
https://www.dewr.gov.au/engineeredstone
There were (apparently) to many hobby-ists and construction companies cutting kitchen benchtops to size with an angle grinder and without PPE or wet saws. You can always leave it to politics and lobbyists to take the easy way out.
Asbestos in vermiculite insulation (Libby) or baby powder (J&J), silica in engineered stone, sandblasting of jeans (Türkiye). It’s often the seemingly innocuous sources that get people to drop their guard.
It’s very hard to hold companies to account that caused workers to be exposed to asbestos one or two decades ago in an occupational setting. As for CF composites, there will be some insights that transfer from occupational exposure to CF dust, but filament manufacturers are rather unlikely to ever face legal challenges for what they throw on the market. Let’s not forget that.
On the bright side, most CF is derived from PAN, so one would need to make sure they don’t put pitch-based fibers into filament.
“In order to predict and manage health risks of the large variety of existing carbon fiber materials, the understanding of the relation between fiber microstructure, fracture morphology and WHO-fiber release propensity must be urgently improved. In the meantime, all handling and processing steps of pitch-based carbon fibers have to be accompanied by precautionary or exposure measurement-controlled safety measures to protect the employees.” – https://www.baua.de/EN/Service/Publications/Essays/article2633.html
graphene is far worse than asbestos.
Can you add some data sources to support that claim?
It’s coming our way in quantity too – I saw a few grams of it, thankfully sealed in a perspex cube, just a few weeks ago.
Make greenish hydrogen from hydrocarbon feedstocks and trap the carbon as graphene. And then embed that in whatever, trapping the carbon. However, what happens when those things get eroded, cut into, or whatever. One destination might be car tyres. Which by their very nature, erode in our midst.
Thank you for the great article and for warning the community!
They used to make airfilters at the building ventilation systems from CF…
At least the filters for vintage soviet GP-5 gas mask contain asbestos. For air filtration, glass fiber filter cloth (bag type, pleated) is not unheard of (but rather coarse in G2-G4 filters, as well as for oil mist separation). But carbon fiber?
Maybe you can find a link to the CF product.
New hack: Carbon fiber reinforced skin!
Tumor-reinforced lungs!
Like a fool, I sanded some CF-PETG prints a little and got the itchies from it. I could see the carbon slivers in there, they show up pretty distinctly. I tried the tape trick to get them out, sometimes it works on cactus spines and fiberglass shards, but the carbon fiber is really “thorny” I guess.
I was a bit surprised in the video where he just rubs the raw filament and gets some carbon particles off. Probably gonna spray some kind of overcoat on my stuff in the future.
For really sticky stuff try facial peel products. They go on wet and set in a few minutes. I’ve had success with that when metal slivers wouldn’t come out any other way. (Now you do need to be prepared for complaints from raiding the supplies of your significant other.)
I’ve always just used a razor blade when they’re completely buried or can’t get them out
Is the strength increase enough to really be worthwhile?
So there are several material properties and those not well versed lump this all into “strength”.
Strength is not stiffness nor is it toughness. Strength is yield or ultimate tensile – the point it deforms or the point it basically breaks (sort of, but practically), stiffness is slope of line on stress strain or how much it bends elastically for a given force and will return (unless you pass yield), and toughness is area under it’s curve or the energy it absorbs when it fails or usually plastically deforms.
So if you need more strength CF/GF printed materials are are barely stronger. 20 – 40% over their base material I commonly see. If you need stiffness they can be double to triple (Sub 2GPA to 6GPA I’ve seen). Toughness doesn’t seem to change that much based on underlying material as the fibers are too short.
Specificity in engineering language matters
The reason Asbestos is detremental to lung health is due to a combination of the sharp ends causing cell damage and it’s biological inertness both of which apply to carbon nanotubes. I suspect therefore that carbon nanotubes will turn out to be just as detrimental.
Yeah exactly, it’s not that asbestos was chemically carcinogenic, it’s basically a mechanical phenomenon
I read somewhere that the issue is that the iron content over time becomes ionised to Fe3 and that’s when it becomes a machete to DNA.
Hmm, but carbon is not biologically inert? I would expect it to be broken down in the body?
This seems (??) easily testable in rats, use an asbestos testing protocol but sub for cf with similar morphology.
Instead of rats, how about using Personal Injury Lawyers?
Because they are already cancerous?
Regular carbon yes, but how does a cell capture it when it is small enough to pass cell membranes?
I’m more worried about the fibers from Magic Erasers. My wife uses like 8 a month….
Those are just abrasives. How does anything still exist in your house if she’s just sanding it all away??
Interesting subject. Although merely fiber safety – adjacent it still looks like the debris of “microplastics-ready” open cell melamine foam is not great either.
Here’s a breadcrumb I found for your further investigation:
“Final Report on the Safety Assessment of Melamine/Formaldehyde Resin” (1995)
https://journals.sagepub.com/doi/10.3109/10915819509083598
Once we get past the cool factor of carbon fiber, there may be room for other composite printing materials. Cellulose nanofiber appears to have drawn considerable attention, but even the regular plant fiber types offer some intriguing possibilities:
(1) Venkatarajan, S.; Athijayamani, A. (2020). “An overview on natural cellulose fiber reinforced polymer composites.” doi:10.1016/j.matpr.2020.09.773
As noted above carcinogenesis seems to be a mechanical feature. Inert, long thin fibres seem to be the particular risk.
Dimensions of elongate mineral particles and cancer: A review.
Ann G. Wylie a, Andrey A. Korchevskiy b
Highlights
•Width of elongate particles is a strong predictor of carcinogenicity
•Asbestiform particles shorter than 5 μm do not significantly contribute to mesothelioma risk
•Short and thick non-asbestiform particles/fragments have negligible cancer potency
•Retention of particles in human lungs tends to select mostly asbestiform variety.
Environmental ResearchVolume 230, 1 August 2023, 114688
Wow, we needed studies to figure out that huffing dust is bad.
No, but we need studies to figure out exactly how bad it is.
We all know that huffing car exhaust is bad, but if they did studies on how bad it is they might have realized that leaded gas was a problem much earlier.
Getting any kind of contaminant in your lungs is bad. There is no reason to treat any contaminant more favourably over another. Just treat all substances that have a particulate components as bad, which is pretty much everything!
I’m 90% sure that some particles are worse than others, like long, hard, thin, and sharp ones (asbestos and cnts) as well as ones with sharp edges from being recently cut (granite countertop dust) are worse than smoothly rounded particles. Also, particles that your body can easily breakdown and remove (dead cells) are not as bad as ones it can’t breakdown.
Unless you are the kind of person who wears a mask 24/7, it’s useful to know that in some situations you should wear protection even if there does not appear to be much dust.
“There is no reason to treat any contaminant more favourably over another.”
Huh? Can’t tell if you’re kidding or not. Sometimes I’m going to want a P95 and sometimes a P100 and sometimes a frickin’ pressurized moon suit. Not all particulates warrant the same level of care.
Without watching the video, seems like alarmist nonsense. Clickbait title and based on the article the contents consist of “looks similar under the microscope”. You should wear PPE when working with dust producing things in general, but calling something the new asbestos with seemingly zero proof is a bit much.
Well, then watch it to see whether your jumping to conclusions .. anyway, I find there should be more such videos.
It’s about critical observation, first and foremost, how handling of the fresh filament unexpectedly already causes particulate shedding, how to reproduce the observation with limited means, and it concludes thoughts on how to mitigate the implied risk (switching to core-shell CF filament types, more restrained use of CF materials).
Sure, it could have been twice as long and added a full literature review, but good observation is valid on its own, even if it doesn’t reward us with definitive answers right away.
Teflon scandal all over again.
Today 99% of ppl contain microplastics including cancer inducing Teflon.
Teflon is food safe though
PTFE itself hasn’t been implicated, but it is often contaminated with various PFAS chemicals used either in the manufacturing process or to make it adhere to things like frying pans.
Which raises an interesting question. I have never been able to determine if there is an LD50 equivalent for carcinogens. All data sheets seem to say is “carcinogenic“ or “highly carcinogenic”. Isn’t there some better qualification than that?
There’s no definite cut-off point for where asbestos and other carcinogens change from harmless to harmful, but increased exposure definitely raises the cases of cancer and other negative health outcomes. Since asbestos for example is just a naturally occurring mineral, some exposure is pretty much unavoidable, but there are some ballpark figures for what exposure limits are deemed acceptable. As per e.g. the CDC: https://www.atsdr.cdc.gov/toxprofiles/tp61.pdf
Most carcinogens seem to rely on effectively chance whether they cause cancer or not. This means that exposure levels, duration, one’s overall health, effectiveness of one’s immune system, etc. all play a role in the health outcome. Or why someone can inhale carcinogenic, radioactive tobacco smoke for decades and be fine, while someone else goes on to develop lung cancer or similar before they hit retirement age.
Tl;dr: if it causes DNA damage via some mechanism, it’s a carcinogen, but like with russian roulette, you may be lucky.
LD50 is a measurement to determine the amount of material that will kill 50% of tested organisms in an acute exposure (short time duration, with dosage and exposure duration stated). Many carcinogens take years to have an effect, and those effects may or may not be cumulative, so an LD50 is not the right measure to use to quantify carcinogenic potential. Others readers may have that information.
Half the junk I own is carbon fiber. I’m about to put on my carbon fiber hard hat and go to work ffs.
If you don’t get brain cancer then that means it’s safe.
I used to work in a fabrication shop as a welder, where we used sheets of asbestos sandwiched with perforated zinc metal sheets. We had to use jig saws and drills on the sheets, but we also had to wear respirators while doing so. Cleaners went around the shop, constantly, cleaning up any dust with the central vac system. Concern arose about using the asbestos, so a union representative came to speak to us about it. He said the blue asbestos was of greater concern than the white, and we were only using the white. He also said there is more asbestos in the air in the city center than in our shop, due to the asbestos brake linings of many vehicles. That’s why asbestos-lined brakes were banned. To make that determination about the amount of asbestos in our shop, we wore devices that had a battery pump on our belts, and a special filter very close to our mouths. Of course, what we were told may not have been true because production had to continue.
Since those days I’ve worked in construction with filth in the air, and no masks. Today I’m retired but my doctor has found a small problem with my breathing and sent me for tests. I’m not 100% but I don’t have any problems because of it. I’m seventy-eight years old and still ride a bike twice a day, a total of eight miles. I would guess the construction sites were worse than the fab shop with its asbestos sheets.
Wow! Jump off the diving board into the deep end of alarmism.
Do you have any evidence that carbon fiber could cause lung cancer like asbestos?
Don’t go comparing things to asbestos unless you have some evidence that it causes issues like asbestos.
Yes, wearing an N95 mask is good. But on the other hand, we breath all sorts of dust that can get into our lungs and most of it is not as severe of a risk as asbestos, so don’t go throwing claims of similarity to asbestos about so lightly.
Reading the cited paper might be a good start on your path to becoming educated on this subject.
You can buy Hemp fiber reinforced PLA filament.
@Maya Posch
N95 respirators aren’t certified to filter out asbestos and will not filter out the small particles that tend to get lodged deepest in your lungs. You need N100, P100, or a similarly rated respirator to filter out asbestos.
Hence the ‘rated for filtering out asbestos’ qualifier. Whether N95 or better is less important than whether it is certified for filtering out asbestos-like fibres.
I noted this years ago, just after nanotubes were introduced. Just wait for the banning of plastic utensils as well.