Almost 60% of the 35 dishwashing detergent brands tested by the market watchdog contain allergens and preservatives. Photo: HK Consumer Council

Many dishwashing detergent brands tested by the Hong Kong Consumer Council – 21 out of the 35 – were found contain allergens and preservatives, despite packaging touting “all natural ingredients” or “mild and gentle to hands”.

The council has urged consumers to read ingredient labeling carefully and not be hoodwinked by misleading catchwords.

A host of allergic preservatives such as methylisothiazolinone (MIT), methylchloroisothiazolinone (CMIT) and benzisothiazolinone were found in the 21 samples, with the AXE Supra ultra-dense detergent containing the highest amount of MIT and CMIT.

Five of the detergents even claimed that their products were safe to wash ready-to-eat fruit and vegetables.

Consumers in daily repeated contact with detergents containing high amounts of allergy-inducing preservatives may result in an allergic reaction or even dermatitis on their hands.

Worse, a significant number of brands found to contain these preservatives had not included the substances in their ingredient labeling.

The tests were carried out following a recommendation from the German Cosmetic, Toiletry, Perfumery and Detergent Association for a quality assessment of the cleaning performance of hand dishwashing detergents.

An expert with the market watchdog suggested that consumers not use detergent to wash fruit and vegetables so they avoid contact or ingestion of residues of allergens and preservatives that may remain on the surface.

There was also a wide disparity in regard to cleaning with the brands tested. With the same drops of detergent, the number of dishes the best performing brand could wash during the test was as much as five times the corresponding figure of the worst performing brand.

If dishes are very oily and have “stubborn” stains, they can be soaked in warm water for a few minutes to help the fat and oil decompose, before being rinsed with detergent.