That would depend on the chemical and your personal values. Lots of people now are attempting to go back to the basics and use all-natural or as close to all-natural products as possible. Olive oil, tea tree oil, witchhazel, flower and fruit extracts are among the most popular--nothing synthetic here. With the level of vanity in our society, however, there are chemicals that have been created to decrease the appearance of lines and wrinkles, cellulite, etc. If they are not toxic and harmful, there shouldn't be a problem.
The majority of skin care products, synthetic as well as natural, contains the followings, in a proportion or other:
Emolients:they are used for their protective rol and their prevention job which they are realising, meaning that they keep away the dryness of the skin. It is known the fact that the water in the skin does evaporate quickly and in order to keep it much longer, emulsions are used, emulsins being a combination between water and oils.
The difference between natural and synthetic emolients is that the natural ones are more friendly with the skin, and they are easily metabolised by the skin's enzymes. They are not occlusive as the synthetic are.
Humectants: they have to attract the water from the environment and lock it inside the skin.
Keratin, collagen are natural humectants, friendly with the skin, but not friendly when their origin is animal one.
Phospholipidis obtained from lecithin are hygroscopic and the process of keeping skin moisturised is a non occlusive one.
Emulsifiers: They have to keep together substances that usually doesn't blend.
Natural emulsifiers are obtained from berries and leaves.
Surfactants: they are present in cleansers and thei job is to disolve oils and to form a dirt suspension.
Natural saponons are more gentle with the skin, hair and scalp, the process of removing oils being mild and inoffensive one.
Preservatives: products go bad after a period of time, so, beside the freezing process which preserves the properties of products intact, natural preservatives are the most indicated preserving manner.
Natural preservatives: grapefruit seeds, tee tree essential oil, thyme essential oil etc.