The need for preservatives in cosmetic products

I disagree with the current hype of preservative-free cosmetics. I think it is not safe to produce such cosmetics. Also I often believe it is not true and cosmetic companies are lying to us.

Cosmetic preservatives have not been a long for that long. However their introduction was necessary when water based cosmetics were placed on the market so that they could be stored for a longer period of time.
In the beginning (before 1900's) phenol and sodium benzoate were used as preservatives. Later in the 1920's paragons and formaldehydes were introduced as preservatives. Further years brought many new preservatives on the market as well as blends and naturally-derived preservatives.

Why are preservatives need in our beauty products?
Well this is because along with principle ingredients such as water and oil our cosmetic products often contain ingredients such as glycerin or sorbitol, which provides a source of carbon for microorganisms. Therefore cosmetics can easily get infected with bacteria and fungi or other microorganisms (just like food!).

There are two ways our cosmetic products can get contaminated - through primary and secondary contamination.
Primary contamination is usually caused by contaminated water or other raw products out of which the cosmetic is made. Secondary contamination usually arises from the consumer having dirty hands (with bacteria on them) and contaminating e.g. the cream.

Preservatives can cause allergies and irritate skin that is why they should always be used at the smallest necessary amount. Usually this is around at 1%.

There are some preservatives and germicides which can be used in cosmetics and they can still be claimed as preservative-free, this includes 1,2-hexanediol, phenoxyethanol or citrus grandis seed extract and others. Also if a product contains higher amounts of ethanol (20% or above) there is no need to add preservatives to the product.

Despite their bad faim parabens are rare causes of skin allergies. They are also not responsible for a increase in breast cancer as some people claim. They are actually one of the safer preservatives to use in your cosmetic products. That is why avoiding products containing parabens makes no sense. Formaldehyde releasers are much less friendly and are banned form cosmetic products in some countries such as Japan. Also isothiazolinone type preservatives are also more prone to cause allergic reactions.

It is without doubt that preservatives should be used with caution and at smallest possible amounts but they SHOULD be used in all cosmetic products which contain water and will not immediately be used.

What is your opinion about using preservatives in DIY cosmetics? Which preservatives do you most often use yourself?