Danish eye drops containing toxic preservative widely used

Thousands of Danes regularly use eye drops to relieve irritated, tired, or red eyes, but many of these products contain the toxic preservative benzalkonium chloride (BAK), reports DR.

BAK, also found in household cleaners like Rodalon, can damage the surface cells of the eye, causing redness, irritation, and in severe cases, pain and blurred vision, according to Miriam Kolko, professor at the University of Copenhagen and senior consultant at Rigshospitalet’s Department of Ophthalmology.

Kolko argues that BAK is unnecessary in modern eye drops, as it was originally used to prevent bacterial growth but is no longer needed for artificial tears. She calls for an immediate ban, noting that Denmark is among the countries with the highest use of BAK-containing eye drops, with up to 40% of over-the-counter artificial tears containing the preservative.

The Danish Eye Association, representing patients with eye diseases, has long pushed for a ban. Director Marijke Vittrup calls it “indecent” to allow toxic preservatives in non-essential products, describing the situation as “baroque and self-contradictory” for consumers to use drops that may worsen their symptoms.

The Danish Medicines Agency, however, has ruled out a ban. In a written response, the agency states that BAK is EU-approved for preventing harmful bacterial growth and that most eye drops on the market do not contain it. It advises patients to check the package insert for BAK and switch to alternative products if they experience side effects. The agency also notes that non-prescription eye drops should carry a CE mark, indicating compliance with medical device regulations.