Polysorbate, in its original form, is a harmless sorbitol (vegetable based sugar alcohol).
Polysorbates are used as fragrance ingredients, emulsifying agents, and as surfactants (nonionic detergents).
Emulsifiers help all of the other ingredients in a product stay mixed up.
When Polysorbate has a 20, 40, 60, 80 at the end, it has been treated with 20 (40, 60, or 80) parts of ethylene oxide (ethoxylated).
The scientific literature identifies limited evidence of sensory organ toxicity from Polysorbate 20.
Residual (referred to as contamination) ethylene oxide and 1,4-dioxane, which are a by-product of the chemical reaction to make polysorbate 20 is unavoidable.
Manufacturers using Polysorbate 20 would have a hard time claiming Polysorbates are "free" of residual ethylene oxide and 1,4-dioxane.
Even though they do use processing steps to reduce the residual ethylene oxide and 1,4-dioxane to low levels, it is unlikely they will be "completely free of these contaminants".
Manufacturers who use Polysorbate 20 in their products will argue that the low amounts of contaminants (likely in the 1-10 parts per million range) are so low they won't cause health issues. They would argue that this chemical, when used at low concentrations in the final product, is considered non-toxic.
Since the non-toxic claim can't be validated, the question is ... why use a product on your dog when there are safer alternatives without Polysorbate 20 in it?
If your dog's food had contamination, would you feed it to them even knowing it is in low concentration?
Of course you wouldn't, so why would you a product with contamination on their body?
Another consideration when it comes to ingredients and bathing your dog...
When you dog is in the bath, the warm water works to open the skin pores which increases the absorption of the ingredients through the skin and into the body.
Again, why risk any questionable ingredients in your dog's shampoo when 4-Legger makes safe and non-toxic USDA Certified Organic Dog Shampoo without synthetic ingredients?
Learn more about 4-Legger's Organic Dog Shampoo and our Clean Ingredients.
Note: Polysorbate 20 is also commonly called Tween 20.