Re:Strong != hard (Score 1)

And natural - can't forget that. No nasty nano this and nano that.

Oak trees give off isoprene, which is converted to formaldehyde by sunlight and water.

Formaldehyde molecules are both nasty and nano sized.

Not to say Oak trees are bad for you, but it is good to remember that Natural != Healthy. There are plenty of naturally occurring poisons.