I feel that you are making "much ado about nothing".
I don't mean offense, but if you want to avoid toxins... then don't do nails. Don't eat. Don't bathe and don't wear makeup. And omg, DON'T BREATHE.
There is a website
Skin Deep: Cosmetic Safety Reviews that will list 'toxins' and 'carcinogens' for just about every makeup, hand lotion, soap, moisturizer, shower gel, etc etc out there.
How about Dove soap? Think it's great for your skin? Lovely PH balance, etc etc? Dermatologists recommend it...
As per the above mentioned site, PLEASE read this:
http://www.cosmeticsdatabase.com/product.php?prod_id=163637
Johnsons & Johnsons Baby shampoo..... safe for baby?
http://www.cosmeticsdatabase.com/product.php?prod_id=147083
If you read the above two links, you should be freaking out, right about now.
ALCOHOL can be toxic, if not used correctly.
I think perhaps you need to have a realistic grasp on the meaning of the word 'toxic'.
To define toxic:
Having a chemical nature that is harmful to health or lethal if consumed or otherwise entering into the body in sufficient quantities
en.wiktionary.org/wiki/toxic
toxicity - the degree to which something is poisonous
toxicity - perniciousness: grave harmfulness or deadliness
wordnet.princeton.edu/perl/webwn
Toxics - Toxicity is the degree to which a substance is able to damage an exposed organism. Toxicity can refer to the effect on a whole organism, such as a human, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell (cytotoxicity) or an organ (organotoxicity) such ...
en.wikipedia.org/wiki/Toxics
Please note above, the words "the degree to which" or "sufficient quantities".
As I said earlier.....ANYTHING can be toxic if there's
too much of it.
You need to worry more about the germs that are on your client's hands when he/she walks in the door than you do about the 'toxity' of scrubfresh. And if you're worried about toxity, then OMG.... don't ask them to wash their hands with soap... it might poison them.