We rate BHA / BHT, PEGs, petrochemicals, parabens, phthalates, formaldehyde releasing agents, siloxanes, sulfates,fragrance/parfum and non-biodegradable ingredients 8 - 10 Dirty. We believe that those chemicals do not belong in the products we use on a daily basis, no matter how high or how low of a concentration is present. Some people argue that low doses of those ingredients are harmless, but we take into account the fact that most of us use more than just one product and how even in low concentrations, those controversial chemicals could have compounded effects or react with each other, especially over a long period of time. The health impact of being exposed to the chemical cocktail effect is unknown. The debate on how much toxic chemicals should be allowed in your products is similar to arguing how much MSG should be in your food. In both cases, we believe there shouldn't be any.