It’s important to us that every product is safe for people and the planet, which is why we put our formulas through third-party independent, nontoxic certification by MADE SAFE’s board of scientists, who investigate ingredients and ingredient combinations. We use phenethyl alcohol and ethylhexylglycerin as the preservation system for our water-based products. Both are approved by MADE SAFE and are rated a "1" by the Environmental Working Group, which is the safest possible score.