British Society of Cutaneous Allergy (BCSA)


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 octylisothiazolinone.

What is octylisothiazolinone?

Octylisothiazolinone (2-n-Octyl-4-isothiazolin-3-one) is a domestic and industrial preservative used to kill fungi and bacteria.

What are some products that contain octylisothiazolinone?

  • Paints (water-based) and varnishes
  • Polish
  • Metalworking fluids
  • Glues and glue removers
  • Detergents, eg laundry washing liquids
  • Leather items, eg belts, shoes, watch-straps, sofas, car seats
  • Some fabrics/ textiles, including mattresses
  • Textile sprays
  • Windscreen products
  • Gardening and DIY products
  • Printing inks and toner
  • Air fresheners
  • Pesticides.

Industrial synonyms

  • Skane M-8
  • Kathon LM
  • Kathon 893
  • Kathon 4200
  • Pancil, Kw1000.

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 octylisothiazolinone 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: 2019