British Society of Cutaneous Allergy (BCSA)

Quaternium 15

What are the aims of this patient information leaflet?

This leaflet has been written to help you understand more about your contact allergy. It tells you what a contact allergy is, what causes this allergy and what you can do about it.

What is contact allergy?

Dermatitis, also known as eczema, describes a type of inflammation of the skin. Contact dermatitis or contact eczema is a term used when this inflammation is caused by direct or indirect skin contact with something in your environment. Allergic contact dermatitis occurs when your immune system causes allergy to a very specific chemical or substance that has been in contact with the skin.

What causes your specific allergy?

Your patch tests indicate that you have a contact allergy to quaternium 15.

What is quaternium 15?

It is a preservative frequently used in household products. It may be known as Dowicil 200 in industrial products. Cosmetics require labelling in European Union countries where it will be known as Quaternium 15 but household products do not require labelling.

What are some products that contain quaternium 15?

Cosmetics and toiletries

  • Hand and face creams, moisturisers
  • Shampoo, conditioner and hairdressing products
  • Mascara and make up
  • Wet wipes.


  • Medicated shampoos e.g. ketoconazole shampoo
  • Skin cream, emollients (moisturisers), ointments and lotions
  • Suppositories
  • Antiseptic wipes.


  • Washing powder and detergent
  • Fabric softener.


  • Paints
  • Cutting oils and cooling fluids.

Remember, always check the label, these lists can never be complete and ingredients change.

How can I manage my allergy?

This means that you should avoid putting products containing quaternium 15 onto your skin in the future.

Self-care (what can I do?)

Always check the ingredient listing on the product, package or package insert as these lists can never be complete and ingredients change. This is particularly important for any products purchased outside the EU where some allergens may not be banned.

Created: 2016