Quote Originally Posted by Photo Engineer View Post
It is merely a matter of EG vs PG and toxicity and also the ability to measure tiny quantities.

Thanks, PE -- I should have looked it up first.

I mix 7 oz. with water to make a gallon of stock solution, then the students take one oz. of the stock to make a gallon of working solution. Very strange stuff.

Contains OCTYLPHENOXYPOLYETHOXYETHANOL, which according to the MSDS, does not sound too bad (keep it out of the eyes and the concentrate off the skin.) Also, POLYETHYLENE GLYCOL -- I assume that is the PG you referred to.