British Society of Cutaneous Allergy (BCSA)

Diazolidinyl urea or Imidazolidinyl urea

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 diazolidinyl urea or imidazolidinyl urea.

What is diazolidinyl urea or imidazolidinyl urea?

Diazolidinyl urea and imidazolidinyl urea are preservatives. These chemicals are closely related and if you are allergic to one you may react to both.

What are some products that contain diazolidinyl urea or imidazolidinyl urea?

Cosmetics and toiletries

  • Hand and face creams, moisturisers, deodorants
  • Shampoo, conditioner and hairdressing products
  • Mascara and make up, wet wipes
  • Self-tanning creams, sunscreens.


  • Skin cream, emollients (moisturisers), ointments and lotions
  • Nizoral anti-dandruff shampoo
  • Cutivate cream
  • Radian massage cream, Radian B muscle rub
  • Ultrasound gel
  • Anti-microbial hand washes.


  • ┬áPet care products including shampoos.


  • Paints
  • Cutting oils and cooling fluids.

Cosmetics require labelling in European Union countries where the chemicals will be known as diazolidinyl urea or imidazolidinyl urea but household products do not require labelling. Diazolidinyl urea may also be known as Germall II and imidazolidinyl urea as Germall 115 in industrial or household products. Imidazolidinyl urea may be known as imidurea in some medicines.

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 diazolidinyl urea or imidazolidinyl urea 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