BikeBiz

I didn't know that carbon nanotubes are used in bicycles. How are they used? Are you sure that there is not some confusion here with carbon tubing, as opposed to nanotubes?

Aside from the manufacture of the nanotubes and possibly the frames exposure seems unlikely, but: -

Are Carbon frames carefully cleaned of nanotube debris / fibres before sale?

Surely, the biggest danger from nanotubes for the cyclist would be in the event of a crash where serious damage to the frame occurs. It must be a possibility that unbonded nanotubes could be released. Public liability!

I think from consumer side the problem really only comes when the frame will get damaged.
But think about the workers in China which are grinding that material by hand, most times without inhalation protection and without any water for bonding possible dust!!! These guys are really in trouble and I'm sure they don't know.
By the way, we in KTM do not use any Nanotubing, but have very lightweight and durable frames as well.

I agree danger to the end user must be tiny once the nano tubes are added to resin and cured, even in a failure the amount released if any must be tiny to.

If these 'scientists' worried more about curing cancer im sure we would be in a better would now!!!

It seems anything and everything is bad for us.

I agree that the resin locks in these fibres and they are only a danger in manufacture and also when the bike breaks (but in this case exposure is brief). In short, the companies using this product should ensure their manufacturer's protect their workers adequately as the Chinese work ethic will change in time and legal cases down the line will no doubt be raised. It happened here in Africa with Asbestos mines (I think Rio Tinto had to pay quite a lot in damages) and it was based on the fact that they knew of the dangers but did not act on it. We as manufacturers (not of bikes though!) ensure any of our inputs are not harmful or that adequate protection is used.

Even if there's a proven link to cancer, there would be almost zero danger to consumers. Carbon nanotubes are 'embedded' into host materials. However, as others point out, manufacturers of carbon nanotubes will have to make sure their facilities are squeaky-clean.

I've updated the story.

Same comment as Max. Carbon nano tubes are not the same as carbon fibre, the material used to make carbon reinforced composites so it looks like a bit of half baked reporting of a half baked story.

Not read the original paper but the press release, which I assume the jounos are using, seem to be full of ifs, buts and maybes culminating in the declaration for a need for more research. I wonder if the group writing the paper are looking for funding at the moment.

The most startling fact for me in this whole saga is the fact that mice are making bike parts. Tennis rackets I could live with but I don't want rodents making my handlebars thank you very much.

cutting of carbon, eg fork steerers and seat columns is already highly toxic, with the microscopic fibres staying in the atmosphere. No cutting carbon in our workshop!

Just for DocB I have updated the story with a link to the paper as well as quoting the full abstract.

In response to Max and DocB, Carbon Nanotube is used on bikes - Ever wondered what the CNT stands for in Easton bars and forks? - Carbon Nanotube Technology!

I don't think crashing or bar failure is a realistic risk, as it is unlikely that you are going to be near enough the failure and it will generally happen outdoors where it will be well ventilated. The real risk away from the production line is for the shop mechanics and home mechanics. Leaning over a set of carbon forks while cutting the steerer down is a great way to inhale. I've know for a couple of years to wear a filter mask in the workshop while trimming carbon forks and bars - but how many others are aware of this?

I've updated the story with a link to a 2005 BikeBiz story reporting on exactly the same health concerns, re asbestos.

BikeBiz has carried lots of nanotube stories, most of them to do with Easton.

In other breaking news, researchers have determined that saliva may be linked to stomach cancer, but only when swallowed in small amounts over a long period of time.

Seriously though, even if free CNT particles are exactly as dangerous as asbestos the relative risk to the consumer of inadvertent exposure is ridiculously low due to the limited quantities involved and the physical form of the products in question.

Those wishing to make a more detailed comparison of the two materials can find linked information here: http://en.wikipedi...estos and here:
http://en.wikipedi..._Tube

There's also, as with asbestos, going to be a big end-of-life risk, when these frames and parts are junked. Asbestos is perfectly safe if not disturbed (our old house has quite a bit of it) but removing it is a serious undertaking.

DocB - have you ever read a paper which says "no more research is needed"? Papers always say that, and it's always true - you never stop investigating things.

Ben, you are quite right in your last comment. Its just that time spent adjudicating on SERC research panels left me a little wary about the motives when "scientifically" based scare stories appeared in the national media.

Carlton, does the abstract actually say this....

"Nature Nanotechnology journal said inhalation of carbon nanotubes by mice led to inflammation and lesions."

....which is a quote from your piece?

The abstract says exactly that:

"Here we show that exposing ... to long multiwalled carbon nanotubes results in ... inflammation and the formation of lesions"

Edited for clarity.

Don't think it does.... inhalation is not mentioned in the abstract as far as I can see and Carlton does report that it says that inhalation led to lesions.

Nit picking, DocB? Clearly, the mice are exposed to the nanotubeswith their chests cut open, then there's inflammation. It might take a while for a mouse to breathe in the material in sufficient quantities.

However, the result is meant to replicate inhalation.

Jeez.

The risks per gram of inhaled substance may eventually be proven to be directly comparable. Even so, the nature of the structures involved and the huge differences in relative amounts used limit the potential danger.

Asbestos is comparatively inexpensive and plentiful. Thousands (millions?) of metric tons of it have been mined, mixed and sprayed as insulation and fireproofing in a huge variety of applications over a period of many decades. The risks have been documented over many hundreds of years.

CNT on the other hand are very new technology, manufactured in comparatively tiny quantities and applied sparingly. The methods of construction, use and destruction are well-documented and can be easily controlled.

Finding out about this at this stage is very good. Protecting those who are subject to exposure will not be difficult or expensive. Those who use products that contain CNT are very unlikely to be exposed to risk from them, but those who fabricate, modify or destroy them need to be protected.

PS - Implanting the substance directly into abdominal tissue is not the same as having the test animals inhale the substance. It is a faster, less expensive way to determine if exposure to the substance has negative effects. Once that has been established the next logical step is to attempt to quantify the relative risk under different levels and types of exposure.

Sorry Carlton but I was trained as a scientist and nit picking is what scientists do. Its the way you get a clear understanding of how best to interpret a set of data. Its a way of developing consensus as well as crystallising disagreement.

Your assertion that the work showed that inhalation led to lesions seemed to be factually incorrect and that needed to be pointed out. The idea that inhalation might lead to carcinoma can be proposed from the information given but it seems to be a very long way from having been demonstrated.

I believe my piece had sufficient caveats.

With all greatest respect, DocB (ie I'm about to insult you), there's a world of difference between scientific nit-picking and pedantry.

The method of delivery to the mesothelium is different - because it's a lot harder to make a mouse inhale dust than it is to apply the dust directly - but I can't see that being a big deal. The effects of asbestos have already shown that the tiny fibres have no problem reaching the mesothelial membrane of the lungs, so similar carbon nanofibres should behave in a similar manner.

The danger of asbestos isn't a chemical one - the chemical makeup of asbestos is nothing to do with the danger, the danger comes from the irritation and scarring of the tiny sharp fibres.

There are still questions, and more investigation is needed. For one thing, long straight buckytubes are rare - they normally coil and spiral up. For another thing, humans have been breathing these things in for thousands of years, as they're present in small quantities in smoke from fires, so perhaps there's an inherited resistance which isn't present in mice, which have never discovered fire.

However, I think the fact that scarring occurred in the mice negates the first point, and the fact that humans aren't resistant to the mechanically similar asbestos fibres negates the second.

Daner: you're quite right - but isn't the time to spot a potential problem now, before millions of tonnes of CNT have been manufactured? If we know it's a problem now, then workers can be protected, and proper end-of-life proceedures can be implemented if necessary.

"Nature Nanotechnology journal said inhalation of carbon nanotubes by mice led to inflammation and lesions".

is a quotation of a complete sentence from your piece.

Clear, simple, no caveats, but I think that I might be correct in describing it as an inaccurate interpretation of what is said in the abstract.

Nit picking? Pedantry? I prefer to think if it as critical appraisal in an attempt to ensure that the world is as well informed as they can be. A scientific rather than a journalistic trait perhaps.

Well, you're both right. Or both wrong ;-)

Carlton was wrong in saying that inhalation led to lesions - that wasn't specifically shown. But you're being a bit pedantic as well - the method used is perfectly comparable to inhalation, so implying that this somehow negates the result is false.

The Royal Society http://royalsociety.org/ reported that even normally non-toxic materials when made into nanoparticles should be treated as entirely new substances.

I think that this is the article.
http://tinyurl.com/6nrf3e

If you are concerned about workers in China, stop buying doorbusters at Walmart! And don't buy nanotubes if you are really worried about cancer in the workers. The world's desire for lower and lower prices is allowing these bad employment practices to go on (poor ventilation, lack of safety equipment, low wages). It starts at your house. Buy from reputable companies, with reputable employment compliance programs and reputable QC programs. Stop buying cheap crap! You get what you pay for and you get what you deserve.

Ben -

I didn't mean to minimize the potential danger, just to point out the positive in that this is a matter of dealing proactively with a problem that is as yet very limited in scope. Much better than finding out after the fact that there are millions of tons of potentially lethal substances that have been applied in rather unstable matrices in buildings, ships and other structures worldwide.

Absolutely - and sorry, I shouldn't have skim-read your comment ;-)

Can we have editing ability on these comments please?

So the length of the nanotubes prevents the lungs from expelling them, thus the nanotubes behave similar to asbestos particles. Is there another way to get your lungs to expel the nanotubes? or to clean or flush your lungs? I know mesotheliomia takes years to develop, so even a slow flush might do. Though there may be little risk to consumers, bike mechanics who cut down your fork, seatpost, or handlebars are exposed every day.

So the length of the nanotubes prevents the lungs from expelling them, thus the nanotubes behave similar to asbestos particles. Is there another way to get your lungs to expel the nanotubes? or to clean or flush your lungs? I know mesotheliomia takes years to develop, so even a slow flush might do. Though there may be little risk to consumers, bike mechanics who cut down your fork, seatpost, or handlebars are exposed every day.

Not really - the fibres are so tiny that they work their way right in to the alveoli, where they stick...

Apparently the chance of inhaling those particles is extremaly low, as they are electricaly charged and don't get airborne very easily.
You can keep your Easton stuff then:)

You guys need to chill out ! we're cyclists not a bunch of worried soccer moms......
The mice won't know what was going on ....one minute they are running around in wood shavings the next they are smoking a Easton handlebar getting some nasty little particles in their lungs that they can't see.....
but seriously though I had no idea and I retail CNT frames and parts every week in my shop.....Staff meeting tommorow Health and Safety 1st for my employees.

As I have followed the whole CNT process some years ago, I want to precise how these mice killer powder is used.
There is a CNT manufacturer,usually a very large chemical company, with thousands of workers in US or Europe. The largest I know is ARKEMA and it is European, with all the safety procedures linked.
They have the dangerous part of the job and they know it.

The NTC at that stage is already encapsulated in a resin, and delivered in sorts of small pellets who are not nano size any more. These pellets are then used to do a masterbatch being incorporated in resin with a complicated process of dispersion. The master resin is later dilluted to be used for the impregnation of carbon fiber (or just injected if they the resin is thermoplastics)

If a NTC can jump out of a frame, even after an accident, it is a very clever one and deserves our respect.

Seriously, apart the NTC producing company who really know what they are doing, there is no risk in the NTC process. The whole story is very typical of the press junk.

A solution of water and PVA glue can be used to totaly control carbon dust while cutting steerer tubes. It lets NO dust become airborne at all. I have learnt this method while attending an asbestos awareness course. I apply this solution with an inch and a half paint brush to the top of my saw guide before and during the cut.