Hong Kongers may now be considering changing their shampoo brands after the Consumer Council’s announcement on Tuesday that more than half of 60 shampoo samples collected contained a harmful solvent that affects human health.

The watchdog said 38 out of 60 shampoos tested positive for 1,4-dioxane, an ether used in cosmetics, detergents and shampoos which the United States Agency for Toxic Substances and Disease Registry suggests that its long term use could damage liver and kidneys.

According to China’s Safety and Technical Standards for Cosmetics, 1,4-dioxane cannot be used as raw material of cosmetics. However, the banned chemical forms during reactions with other chemicals while manufacturing of the shampoo. While the concentrations of 1,4-dioxane all fell within China’s limit of 30 ppm (parts per million), seven shampoos exceeded the European Union’s limit of 10ppm, ranging from 12ppm to 24ppm.

They are products by Head and Shoulders, Clairol, Pantene, ELENCE2001 and Vidal Sassoon.

Also detected in 12 samples were the allergy-causing preservatives methylisothiazolinone (MIT) and methylchloroisothiazolinone (CMIT), which are often added to inhibit bacteria growth.

One product by Head and Shoulders even contained 0.18ppm of arsenic, an amount slightly below China’s limit of 2ppm.

But the council urged consumers not to be too worried as none of the samples constituted an “immediate” health risk, and advised those with sensitive skin to be extra cautious when making their choices.

(With inputs from South China Morning Post)