Glycerin (E422)

What is glycerin and what is it used for?

Glycerin (glycerol) is a trihydric alcohol found in the structure of all plant and animal fats. It is produced as a by-product when soap or biodiesel is made from fats; it can also be made synthetically. It is also a natural part of fat metabolism in our bodies.

In cosmetics its main job is to attract and hold moisture: it binds water from the air and from the lower layers of the skin to the upper layer, keeping the skin soft and supple. It also stops products from drying out and improves their texture. In food it is used as a humectant, sweetener, solvent and texture regulator.

Which products contain it?

• Moisturising creams and lotions, hand creams and serums
• Soaps, shampoos and toothpastes
• Cakes, sweets and dried fruit that need to stay soft
• Flavouring and colour solutions, some drinks and syrupy products

On cosmetic labels it appears as Glycerin, and on food labels as glycerol or E422. In cosmetics it is usually near the top of the list, just after water.

Is it harmful? The scientific assessment

The independent Cosmetic Ingredient Review (CIR) panel concluded that glycerin is safe in cosmetic use. Glycerin does not irritate the skin, causes allergies extremely rarely and is used freely even in baby products. It is even a key ingredient in some medicines and medical products.

EFSA re-evaluated E422 and stated that, based on the available data, there is no safety concern and no need to set a numerical daily intake limit. When consumed in very large amounts, as with many sugar alcohols, mild effects such as headache, nausea or diarrhoea can occur in sensitive people; these amounts are not reached with a normal diet.

Food- and cosmetic-grade glycerin must be purified. Because products made without following purity rules may contain harmful contaminants, products from reliable sources should be chosen.

Who should be careful?

• Vegans: Glycerin can be obtained from plant or animal fats; the source is usually not stated on the label. If this matters to you, you can ask the manufacturer.
• People using products with very high levels: Pure or very concentrated glycerin can feel sticky and occasionally sting when applied to the skin; diluted products are more comfortable.

What to do when you see it on a label

Glycerin is one of the top ingredients you don't need to worry about seeing on a label. It is one of the most effective and economical sources of moisture for dry skin. It works in a similar way to sodium hyaluronate and panthenol. In food, the presence of E422 does not on its own determine the product's health value; it is generally more meaningful to look at the sugar content and level of processing.