The Consumer Council said on Monday that people should wipe off their lipstick before eating or drinking, after most of the 30 products it tested were found to contain substances that could be harmful.

The council said 24 samples contained a substance called mineral oil saturated hydrocarbons (MOSH), which has been shown in animal tests to damage the liver and spleen.

It said that overseas studies showed that the substance might accumulate in the human body.

Five other lipsticks tested were found to contain traces of another substance, mineral oil aromatic hydrocarbons (MOAH), which may be carcinogenic and damaging to DNA.

Victor Lam, who chairs the council's publicity and community relations committee, said although the levels of MOAH found in the test were not high enough to cause cancer, people should still avoid products containing this substance.

"Although the major component of MOAH detected are not suspected carcinogens, for safety reasons many overseas consumer organisations have recommended that ... consumers should avoid using any lip products with MOAH detected," he said.

Lam added that some of the lipsticks tested contained the heavy metals nickel and cobalt, both of which can cause allergic reactions.