The Consumer Council has found at least one type of heavy metal in almost all of the 30 brands of clay masks it recently tested, with two products exceeding mainland and US limits.

Announcing its findings on Monday, the watchdog said it tested products with retail prices ranging from HK$79 to HK$610.

"The test results revealed that over 90 percent of the models were detected with at least one type of heavy metal. Arsenic was detected in 22 models...[and] lead was detected in 28 models," it said.

"Two models were detected with heavy metals exceeding the maximum limits set by the mainland and the United States."

The watchdog said a clay mask under the "Aromatica" brand exceeded the limits for both arsenic and lead, while an "Apivita" product also contained too much arsenic.

"The test results and product information have been referred to the Customs and Excise Department for follow-up," the watchdog said.

"Although the health risks arising from short-term skin contact with heavy metals is low, prolonged exposure or exposure to high concentrations, or contact through wounds or inflamed skin, may increase the risk of heavy metals being absorbed into the body and accumulating over time."

In response to the consumer body, Aromatica's manufacturer said the product in question was made last year and has since been discontinued.

It added that the heavy metal and fragrance allergen levels detected in the product fully complied with Korean and international standards.

Apivita, for its part, said heavy metals are not a raw material of the clay mask, and that tests are conducted regularly for the product.

The watchdog also called on manufacturers to improve product labelling after finding that three of the samples did not provide a detailed list of ingredients in either Chinese or English.