[sharpeware]

Hi,

My query may seem simple to a wiser chemical mind.

I want to know of a water based solution which may contain one or more solutes which can lower the freezing point of water to below -25'C. The solution must also be cheap. The solution must not be hazardous, toxic, corrosive, flammable, or irritant (so it's something I could poor on my hand, neighbours cat, or my mother's cabbage patch without repercussions).

The reason for the search is a competition between friends which I would very much like to win. The best I have been able to find are deuterated solutes, but even with adding those to water I have not been able to find the best from that group and I'm sure there is better.

Many Thanks

[Arkcon]

I don't get why you went as far as deuterated solvents, replacing a hydrogen atom with a deuterium won't help the solute much, if at all, and certainly not in terms of cost.  There is no shortage of non-toxic antifreeze, there are a couple (as well as some toxic ones) here: http://en.wikipedia.org/wiki/Antifreeze#Primary_agents

[sharpeware]

Arkon, thanks for your reply.

Obviously out of the list the acid based diluted solutes and the poisonous alcohol ones are exempt, so which would you go for propylene glycol or glycerol? Or maybe something else not listed on the linked page?

Thanks again

[curiouscat]

Glycerol's pretty innocuous.

[fledarmus]

Is there a reason for not using salt baths? That is the traditional version. Here are some examples:

http://kubiak.ucsd.edu/manual/pdf/XXI_Solvents.pdf