Women be warned - the mascara, eyeliner or lip gloss that has been sitting in your makeup bag for a year could be putting you at risk of infection.
Dermatologists and makeup specialists say out-of-date products are rife with bacteria, which could attack through scratches and cuts.
"Makeup will getfull of bacteria over time," said Dr Paul Salmon of the Skin Centre in Tauranga.
"Handbags are a dangerous cesspit that many people would be scared of dipping into."
A British study of 1000 woman found the average woman's makeup bag is out of date by four years, with 66 per cent sharing makeup and multiplying the chance of infection.
Eighty-nine per cent of women did not realise cosmetics are required by law to carry certain ingredient labelling.
In New Zealand, new rules for labelling cosmetics were introduced in 2008. They require ingredients for all cosmetic products to be disclosed on the product or the packaging. However, there are no rules stipulating a use-by date must be disclosed.
Freelance makeup artist Allie Simpson says women should be most careful with wet products - such as mascara, liquid eyeliner and lip gloss.
"You can put anything on the body, from boils to conjunctivitis to coldsores, and make yourself very sick from not looking after your makeup or using old products," said Simpson.
"Mascara wands are probably the worst."
Simpson said bacteria is also spread by women who share makeup and apply it near the toilet in their bathroom.
If well-looked after, makeup can be kept for about a year after which you should buy new products.
