Recent tests of face creams by the Consumer Council have found excessive mercury in six products, while only about one- third were clearly labelled with information on expiry dates.
Dermatologist Grace Lam says 12 out of 17 teenagers suffer from acne at some point, according to the American Academy of Dermatology.
But Hong Kong has no specific legislation about labelling for skincare products.
Dr Lam says anti-acne treatments can be effective, 'but for teens who really have problem skin, there is no substitute for medical advice'.
If teens buy over-the-counter products, she says, they should be aware whether they contain effective ingredients, such as benzoyl peroxide.
Benzoyl peroxide, she explains, has exfoliating and anti-bacterial properties that can help slough off dead skin cells. It is found in many over-the-counter acne or blemish skincare products.
Another ingredient, salicylic acid, helps dissolve oils and unclog pores, and is found in many products that treat blackheads or clogged pores.
