Benzalkonium Chloride

What is benzalkonium chloride and what is it used for?

Benzalkonium chloride is a positively charged (cationic) surfactant. This charge makes it an effective biocide that can cling to the negatively charged membranes of bacterial cells and disrupt them. It is effective against many bacteria and some viruses; it is odourless and does not bleach surfaces.

Because of these properties, it is the active ingredient in many disinfectants marketed as a “gentler” alternative to bleach. In the EU, its use as a disinfectant is regulated under the biocidal products legislation.

Which products contain it?

• Surface disinfectant sprays and liquids
• Antibacterial wet wipes
• Some “antibacterial” laundry rinse products
• Some hand sanitisers, eye drops and antiseptics (cosmetic and medicinal uses are outside the scope of this page)

On the label it may appear as “benzalkonium chloride”, “alkyl dimethyl benzyl ammonium chloride” or, more generally, “quaternary ammonium compounds”.

Is it harmful? The scientific assessment

Under the EU CLP classification, concentrated benzalkonium chloride is labelled harmful if swallowed (H302), causing severe skin burns and eye damage (H314) and very toxic to aquatic life with long-lasting effects (H400/H410). The level in household products is low; finished products mostly carry an irritation warning.

As for the airways, many studies of cleaning staff have linked frequent use of disinfectants containing quaternary ammonium, especially in spray form, to asthma symptoms and airway irritation. With occasional use at home this risk is much lower, but it makes sense for people with asthma to be careful.

Another issue is the concern that unnecessarily widespread use may contribute to reduced susceptibility to disinfectants in microorganisms. This is why experts recommend using disinfectants only when they are genuinely needed.

Is it the same as esterquats?

No. Both are cationic substances, but the esterquats used in fabric softeners are designed to make fabric soft, have low toxicity and break down easily. Benzalkonium chloride, on the other hand, is a biocide designed to kill germs. The phrase “cationic surfactants” on a fabric softener label usually refers to esterquats.

What to do when you see it on a label

• For everyday cleaning, water with detergent is often enough; save disinfectant for situations where it is really needed, such as caring for someone who is ill or contact with raw meat.
• Applying the product to a cloth and wiping, rather than spraying, reduces the amount you breathe in.
• On surfaces that come into contact with food, follow the contact time on the label and rinse if required.
• If you have asthma and your symptoms get worse after using disinfectants, you can talk to your doctor.

If it gets into the eyes, rinse with plenty of water for at least 15 minutes; if swallowed, call your local poison control centre (in Türkiye: UZEM, 114).