It is safer to go to the  health food store and look for the natural cosmetics and personal care products. They contain fewer ingredients but they are still very effective. You should keep your cosmetic products properly in order to prevent the bacterial contamination. Don't use other people's   cosmetics directly from the container. You need to apply it with cotton tips or disposable applicators, brushes and spatulas.

Beauty Preservation
All cosmetics and skin care products have preservatives which protect them from the bacterial contamination. Here is the list of ingredient which can break down into formaldehyde, a well known carcinogen, neurotoxin irritant and skin sensitizer:
bromo, 2 nitro propane, 1 diol

diazolidanyl urea

DMDM hydantoin

imidazolanyl urea.

However, you can choose the positive alternative to this harmful ingredients. They are very genlte, effective and and cause less irritation and fewer allergic reactions:
grapeseed oil

phenoxi ethanol

potassium sorbate

sorbic acid

tocopherol (vitamin E)

vitamin A (retinyl)

vitamin C (ascorbic acid).