Risks of working with carbon fibre

[Torchy]

Hi,

Believe me I am the last to raise unnecessary health and safety risks...

There is a lot of conjecture in the aero-modelling community and this is posted on the internet.

Some people feel that carbon fibre nanotubes are sufficiently similar to asbestos fibres to raise alarm bells for the use of a material which is still relatively new in widespread use.

I looked at the Health Protection Agency website but could find nothing. Manufacturers highlight basic handling precautions to prevent skin, eye and lung irritation. Carbon fibre particles are viewed to be non-carcinogenic

I did a couple of Medline searches: 'carbon AND fibre AND health AND risks', then 'Carbon AND fibre AND hazards'. I am happy to email PDF abstracts of the results. It is likely that I have picked up many (most) of the available data but choice of search terms with Medline is critical. I am a frequent user, so I have got used to 'Medline-speak' in designing searches.

There isn't very much research but the risks are being taken seriously in peer-reviewed journals. Evidence supports the 'non-carcinogenic' view but studies (actually I only found one) are short term and in rats.

We are probably more at risk from skin and lung absorption of epoxy etc but I'd just like to outline the precautions Sam and I will be taking.

Handle the fibres with gloves and take care particularly when cutting to cut cleanly (use sharp scissors?) - this may be no barrier to nanotubes but hey ho!

Use of overalls which are washed to remove fibres or use disposable suits.

Use of protective glasses and dust masks particularly when sanding.

Well ventilated area particularly when sanding.

Maybe in 20 years these concerns will be found groundless but...

Any other information people have would be useful. Shoot me down if you like and have the data.

[Clive Everest]

Hi Nigel,
I think that you are very right to be concerned.
I have significant skin rashes whenever I work with epoxy.
I also worry that there maybe some connection with the fact that Jan Gougeon developer of WEST epoxies and many great boats died recently of a long term respiratory illness.

As I understand it Carbon Fibre filaments are around 5um diameter and therefore greater than the diameter needed to present a carcinogenic risk. They can have lots of other unpleasant effects.
Carbon Nano tubes are different they are much smaller. I am not aware of anyone using these, however SP do prepregs with nano tube infused resin. This makes the resin much stiffer, and less prone to micro cracking and much more expensive.
They claim that the nano tubes a capture in the epoxy and are not liberated even when grinding.

There may be an issue if the boat is burnt!
Carbon can continue to be a hazard even when assembled and cured especially if you use it to go to sea.

[Andrew Whapshott]

I was also concerned at this when I began working with Carbon etc, as I know a few people that have been exposed to asbestos, so anything fibre-like I take great care with..

I did read somewhere that it is very unlikely to pose a risk as the fibres break down differently, so the Alveoli in the lung can flush them out a little easier, unlike asbestos.. Also they are more brittle than asbestos so they can be caught before they reach the lung..   Although I'm not sure how true this is so still take every precaution. 

We're all still alive..  I'd have thought Epoxy fumes are likely to be the worse, although you also need to be super careful with Colloidal Silica..

[Torchy]

Hi guys,

I've just checked and it is definitely nanotubes where the concerns are. It seems to be because of the dimensions of the particles and their massive surface area with a potential for absorbing toxic chemicals.

It is worrying that they can cause granulomas in rats which means the immune system is not dealing with them effectively even if they don't actually result in cancers in that study.

The tubes according to something I have read elsewhere puncture the macrophages as they try to 'eat' them, the phage dies and an inflammatory process begins. Some say it is like the process with asbestos.

I'm going to avoid any carbon fibre dust in high concentration but yes...we're all still alive 

[Graham Bridle]

Good news for those of us too kak handed/lazy to ever rub anything down ! Can I start smoking again in compensation ?

[Torchy]

Yes but only if you don't inhale...breathing out is OK, you can do that

[Clive Everest]

Carbon fibre and carbon nano tubes are not the same.
Just as Coal and Diamonds are similar, but not the same.

[Torchy]

Yes, the reason for avoiding carbon fibre dust is not because of nanotubes...just sensible. It just means wearing a mask when sanding, which I think most nowadays do.

The other possibility is wet sanding. Does anybody do that to keep dust down? Does it work with carbon?

PS Sorry my curiosity about nanofibres is taking over...amazing technology. Have found a 2006 HSE report which includes nanofibres, how they are made and potential for health risks. Only 'potential risks' for carbon nanotubes identified btw