Quaternary ammonium compounds aka Quats are synthetic compounds made from Ammonium chloride. They are generally used as preservatives, feel enhancers, cleansers etc.
You will find them in Sunscreens, wet wipes, food items, lubricants etc. They are most popular in haircare prodcuts, specially conditioners.
Quats have a cationic structure that makes them attracted to hair. They form a temporary smooth surface over the hair, which makes them great for detangling.
Qauts consists of a wide range of compounds, and some of these are used in Personal care products.
There is a debate around quats because of the health risks associated with few of these. However, all of these are not bad and we're in the clear as long as we read our labels carefully.
Quats to avoid
Quaternium-15: causes the release of formaldehyde gas that can cause health problems at higher concentrations.
Quaternium-18: Sometimes this is sold mixed with Isopropyl alcohol. This is to make it easier to rinse off, though this isn't always mentioned on the label.
Build-up is another criteria that should be of concern when choosing a product (containing quats). Some quats have more build up potential, than others. Since they have cationic charge, they bond with the hair, rather than just creating a passive film. Some people can use polyquaternium ingredients with no problems, but some of us get build-up from them. Conditioning Polyquaterniums have a build-up that is more like overly-soft or overly slick hair, instead of crusty hair that generally happens with film-formers.
High buildup potential:
- Guar Hydroxypropyltrimonium Chloride
Moderate Build-Up Potential
- Polyquaternium -11
Lower Build-Up Potential