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Comment by Egregore | Hacker News Reader

In the video they show that graphene can be thrown away in compost bin safely, how is it related to all the warnings we have about nanomaterials being dangerous?

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The warnings comparing carbon-nanotubes to asbestos are simply because of the shape of the structure - they are both microscopic needles and our white blood cells don't do a good job of breaking them down.

Not all nanomaterials are dangerous (just as varying sizes of dust are not), but many new materials may adopt unnatural properties that our body doesn't know how to deal with. So there is still handwavyness to it all.

The warnings about nanomaterials are about their applications, not their mere existence. (The rational warnings, anyway.) Graphene is just a form of carbon, like graphite or diamond, neither of which is thought to be particularly hazardous.

http://en.wikipedia.org/wiki/Graphene

True, but for example carbon nanotubes are also just "form of carbon" and they are great for lot of uses, but have about the same effect on human bodies as Asbestos, [1] so asking about this is legimitate.

You're right that Graphene is ok, though.

[1]: https://en.wikipedia.org/wiki/Carbon_nanotube#Toxicity

Not necessarily true. As http://www.scientificamerican.com/article.cfm?id=carbon-nano... explains, the impact that asbestos has on our lungs is a mechanical process, and will be caused by any kind of hard object about the same size.

A lot of nanomaterials have the potential for creating dust in this size, including ones made of pure carbon.

Yes, but this isn't a property unique to nanomaterials -- it's a generic risk common to all materials that can produce fine, abrasive dust. My point is this doesn't represent a nanomaterial risk, it's an ordinary risk in which the source happens to be a nanomaterial. Otherwise asbestos could be classed as a nanomaterial risk after the fact.

Is lunar surface material a nanomaterial? It's certainly nasty stuff and it gets everywhere. It's regarded as one of the primary risks in lunar colonization. Does that make it a nanomaterial?

True, it isn't unique to nanomaterials. However nanomaterials and nanomanufacturing have the prospect of creating a lot of long lasting dust on this scale.

Also it has been the case with every round of technology that there are unexpected risks that turn out to be important. It would be a surprise if nanomaterials failed to bear as yet unknown risks. Particularly once you start doping them with a variety of trace elements to get the properties that you want.

They are dangerous to breathe. They are safe to touch or eat.

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