[url= https://www.europeanpharmaceuticalreview.com/news/69034/carbon-nanotubes-cancer-asbestos/ ]Carbon Nanotubes pose same cancer risk as asbestos[/url]
OK, put into a bit more context, they injected mice with short and long CNT fibres and compared with short and long asbestos fibres and found that the results were similar.
It's been long understood that 'unburnt carbon' carried a potential carcinogenic risk, but the studies on these strucures is one that, though not massively surprising, is pretty important.
I've only skimmed the paper for the time being, but I don't think there are any indications of length of persistance of CNT in the lungs, or whether the effect is the same for resin impregnated or resin bound CNT dust created by cutting manufactured parts, like bars.
Still, better safe eh? HSE recommend FFP3 or FMP3 (or something with a P3 filter) for when dealing with asbestos, probably best not to just use a cheapo decorators mask from the pound shop if you can help it.
We always use a vacuum cleaner to suck away the carbon dust when sawing carbon
Unless it's got appropriate filters, all those nano tubes are small enough to fly straight through the standard hoover filter and out via the exhaust, liberally distributing them over a wider area and greater volume of air than you started with.
Unless it's got appropriate filters, all those nano tubes are small enough to fly straight through the standard hoover filter and out via the exhaust, liberally distributing them over a wider area and greater volume of air than you started with.
+1 for this. DO NOT USE A HOOVER. Its similar to toner, when I was a field engineer for an IT company we were issued special vacuums for toner for the same reason as above.
What's best then if you don't have an asbestos grade mask? Outside so there's lots of ventilation?
Standard vacuum cleaners are a no no. Actually makes the situation worse. As someone said above, printer engineers use special vacuums for a reason.
Henry Hoover will just blow the carbon dust all over the workshop from the exhaust.
What's best then if you don't have an asbestos grade mask? Outside so there's lots of ventilation?
don't do it until you can get one?
[url= http://diy.com/departments/jsp-disposable-valved-fold-flat-respiratory-mask-pack-of-2/1388985_BQ.prd ]B&Q cheap one P3 rated[/url]
Noted - thanks.
I'm not in a bike shop, so it's only the odd bar or steerer every now and then, but for the sake of a few quid, that mask seems a good precaution. I do note that hacksaw cut carbon dust does drop though. Quite heavy. Maybe it's all the resin.
I'm sure similar things have been round before, however the general consensus seemed to be that the CNTs are absorbed over time where asbestos fibres are not, so whilst there is a risk it is not as severe?
If the risk is genuinely as high as asbestos, you'd want far more than a dust mask.
There has been and there is still on going research into CNT and occupational ill health. No point just bunging a ffp3 mask on unless you are fit tested and know how to fit it, are clean shaven etc... Hovers need H type filtration to prevent the redistribution of any fibres. Also worth bearing in mind that the link is with CNT not standard layup carbon fibre. There is a load of research data,but at the moment its very much a "may" rather than "does" which is based on the morphology of fibres being similar. Its been kicking about the occupational hygiene field for at least 15years and still hasn't reached a definitive position yet. The other main issue is that at present there is no epidemiology to support the theory, unlike asbestos
Cut the bars ect under a running tap?
Buy the correct size bars in the first sodding place?
Hold your breath whilst cutting?
And pray you cut it to the right length first time... 😆
Get the bike shop to do it for you?
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To be fair for the amount of exposure your average home fettler will be exposed to - cutting a set of bars and maybe a carbon steerer every few years - would the exposure levels even trigger a course of action?
You are supposed to get a facefit but I've not seen anyone I work with fail to pass the test with a 3m 8835 if they are clean shaven.
While I would agree about taking adequate precautions when cutting materials like carbon fibre.....that article is talking about CNT - carbon nanotubes, which isn't the stuff that handlebars are made out of.
lovewookie - Member.....or whether the effect is the same for resin impregnated or resin bound CNT dust created by cutting manufactured parts, like bars.
There will be dust, but it is not CNT dust.
Unless they're Easton bars
Scienceofficer - MemberUnless they're Easton bars
Aaaah, interesting! I didn't realise CNTs were being used to increase the strength of carbon fibre.
There's an interesting article here, that explains roughly how it works....
I still think the OP article refers to 'loose' carbon nanotubes, rather those that have been loaded into some kind of resin.
Definitely worth taking precautions when cutting any material that can give off a fine dust.
To be fair for the amount of exposure your average home fettler will be exposed to - cutting a set of bars and maybe a carbon steerer every few years - would the exposure levels even trigger a course of action?
no one really knows. It will depend largely on the persistance time in the lungs. Asbestos retention can be months to tens of years, depending type and exposure.
Definitely worth taking precautions when cutting any material that can give off a fine dust.
^^that.
and we are talking about nanotubes here. the tubes in the study were >20um in length, how fine is dust created by sawing? bigger than a PM10 I'd imagine?
Not that I'm suggesting taht loose fibres will be likely, but if they are slightly likely, that's enough for me. 🙂
I still think the OP article refers to 'loose' carbon nanotubes, rather those that have been loaded into some kind of resin.
The dust from cutting bars is going an order of magnitude coarser than nanotubes.
nanotubes - 1nm
wheat flour (as an everyday example) - 1000-100,000nm
To put it another way, you're probably* more likely to develop silicosis as a result of a bit of dusty singletrack or cancer from breathing in a solvent based degreaser, or getting used oil on your skin than you are attributing cancer to cutting down a pair of bars.
If I was manufacturing with them I'd be worried, but then in all likelihood I'd be wearing appropriate PPE anyway to avoid contact with the epoxy.
*opinion not statistic, but I'm usually the arsey H&S person in the room.
yep I agree with TINAS, the research papers also say that the risk is with the manufacture where CNT is used before it is bonded into resin and cured.
Also worth considering that the risk is for respirable sized, non soluble fibres and where you have cut the product you will have a mix inhalable and thorasic sized dust faction with an element of respirable dust (not fibre). "normal" Carbon fibre filaments are too large to present as a risk so again that is not a worry. So if you are handling raw CNT before it is resin bonded during manufacturing then there may be an increased risk but that will be carefully controlled under COSHH regulations. If joe public is cutting a handlebar then what you are getting is a mix of dust which is mainly resin or fibre that is encased in resin and therefore does give the same exposure pathway.
Having said that suitable and sufficient dust control is always a winner
to put into context you are exposed to more known carcinogens and suspect carcinogens having a BBQ 😀
I have one of these hoovers at work - just the job!
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tazzymtb - Member
yep I agree with TINAS, the research papers also say that the risk is with the manufacture where CNT is used before it is bonded into resin and cured.Also worth considering that the risk is for respirable sized, non soluble fibres and where you have cut the product you will have a mix inhalable and thorasic sized dust faction with an element of respirable dust (not fibre). "normal" Carbon fibre filaments are too large to present as a risk so again that is not a worry. So if you are handling raw CNT before it is resin bonded during manufacturing then there may be an increased risk but that will be carefully controlled under COSHH regulations. If joe public is cutting a handlebar then what you are getting is a mix of dust which is mainly resin or fibre that is encased in resin and therefore does give the same exposure pathway.
Having said that suitable and sufficient dust control is always a winner
to put into context you are exposed to more known carcinogens and suspect carcinogens having a BBQ
all this and you look sexy as hell too 😉
rene59 - I'm sure it's great and all but for me, a sex-robot has to be prettier than that
all this and you look sexy as hell too
thanks rocketdog
*is now taking a selfie doing a lunge with my man plunger swinging free and little cowbells on my carbon fibre nipple rings* now where do you want it 😛
Let's someone better let this fella know before it's too late!!! [url= http://singletrackworld.com/forum/topic/classic-ebay-advert ]carbon cutter[/url] 😆
thanks rocketdog*is now taking a selfie doing a lunge with my man plunger swinging free and little cowbells on my carbon fibre nipple rings* now where do you want it
Can you pop it in the rear entrance?