EWG Risk Score:
What is it:
Polyaminopropyl Biguanide is a synthetic polymer used as a preservative and anti-bacterial agent.
Why it's a risk:
Polyaminopropyl Biguanide does not pose much risk other than a slight risk of skin or eye irritation at higher concentrations.
Types of products it's found in:
Contact Solutions, sunscreen, facial products, hair products, body washes and scrubs.
Brands that use this ingredient:
The Purity Project
Although a synthetic ingredient, it is not a terribly dangerous one. It is not known to be mutagenic on mamilian cells, not an endocrine disruptor, not carcinogenic, and has a low toxicity. It is not easily absorbed in to skin, and pretty mild on skin and eyes. One fact that gives me pause is the way in which it works--by breaking the cell wall of the bacteria and damaging its DNA. Anything that damages DNA doesn't sound very good to me. However, the studies that have been done on the ingredient have shown that it's not strong enough to break down mamilian cells--so that's a good thing. The bottom line: although it's not a natural ingredient that I would personally use, if you have to use it (say, in your contact solution) you can breathe a little sigh of relief that it's a safer ingredient.