Why does the super-duper, ultra-pure water I use in lab come with a warning on it?

Question

It's the highest grade you can buy (HPLC grade.)
The bottle says "Avoid Contact with Skin and Eyes."
I didn't know water was so dangerous!!!
I am not going to go out in the rain or take a shower anymore then. Hello stinky pits!!!

Answer 1

Dunroamin is right. You can thank lawyers for all the warning labels in "safe" compounds, like water, sodium chloride, sodium bicarbonate etc.

In theory, bottled lab water is completely safe, but since it's not considered potable, or released for human use, it needs to be labeled w/ various warnings.

Brian L - Sea water is hypertonic compared to human tissue. Why don't you immediately shrivel up when you go swimming in the ocean? Your warning that pure water will hurt you is just as silly.

Answer 2

Only reason I can think of is because distilled water is usually slightly acidic, due to carbonic acid in the water that comes from it absorbing CO2 from the atmosphere during condensation after distillation.

Brian has a good answer.
And yes, Dihydrogen Monoxide can kill people! For a funny site check out http://www.dhmo.org/facts.html.
Amusing to see how the truth, when played to the right way, can be used for the craziest purposes.

Answer 3

Brian's talking rubbish I'm afraid. That's the difference between theory and practice. I've been in the business of high purity water treatment for 30 years. I've paddled in it, been drenched in it, swallowed it, even sat in it and my cells are just fine thank you very much.
The greatest danger is drowning in it !!!

Answer 4

Because it has no salts in it, if it comes in contact with your skin or eyes, the organ in question will absorb the water lickety-split and cause cellular swelling and damage.