O/W or W/O?

Cart

Back 27. 11. 2019

In the cosmetic world, we sometimes need to mix oil and water. We use emulsifiers for this purpose.

When oil and water are mixed by adding an emulsifier, they form two types of emulsions:

- oil in water – O/W (Oil in Water)

- water in oil – W/O (Water in Oil)

The aqueous phase can be water or any hydrophilic liquid (for example a hydrosol, floral water) and the oil phase can in turn consist of a lipophilic substance or a mixture of several (for example oils, fatty esters or fatty alcohols). At the same time, it applies that in both types the aqueous phase is present in a ratio of 60-80 %.

O/W OR W/O – DIFFERENCES

When is it better to use an O/W emulsion and when a W/O emulsion?

Let’s characterize these two types in more detail.

Oil in water type emulsion O/W

In this emulsion the oil is dispersed in the aqueous phase. They are used mainly in cosmetic products with a moisturizing effect (these emulsions spread easily, they are lighter, because the aqueous phase is the external phase). At the same time, they are used in rinse-off products, because they are easy to wash off. As far as the use of an emulsifier is concerned, they require the use of several emulsifiers.

O/W emulsions are more prone to microbiological activity, therefore they need to be properly preserved.

An O/W emulsion shows electrical conductivity.

You can thicken these emulsions (increase the viscosity) by adding natural thickeners such as xanthan gum, konjac powder, carrageenan, etc.

Water in oil type emulsion W/O

In this emulsion, drops of water are dispersed in oil. These emulsions are used in products intended for dry and sensitive skin, but also in products for skin care during the winter period (they can be greasy, heavier, because the oil phase is the external phase). They are most commonly used in creams, sunscreens and in most make-up products (because W/O emulsions are water-resistant, some even completely water-proof). The production of a W/O emulsion is more demanding than the production of O/W emulsions. When creating this emulsion, one emulsifier is sufficient for you, but the number of suitable emulsifiers is limited.

Since in a W/O emulsion the aqueous phase is actually hidden in the oil phase, they are easier to preserve and are less prone to microbiological contamination (we will deal with preservatives and the preservation of products in more detail).

A W/O emulsion does not show conductivity. Thickeners have no effect on the viscosity of W/O emulsions. You will increase the viscosity by using waxes.

We believe that we have briefly explained the issue of mixing oil and water for you in the article.

If you know of tricks and ideas that could improve our posts, write to us at marketing@handymade.sk