Uh oh.. I'm a goner then - lead, AS3, AS5, used engine oil, stainless braid that's like a hypodermic - believe me, it's all been in my skin at one point in time..
Oh yeah, I forgot petrol (man that stings if you get it in your eye!).
And another top tip - brake fluid tastes vile, I don't recommend starting a syphon by sucking.
Mercury, though.. that I wouldn't play with - Mercury vapour is highly carcinogenic.
Ok.. I have no concept of personal safety