The next Mac lipstick or eyeshadow you buy in Sydney could be counterfeit and may even burn your face.

More than 8000 counterfeit cosmetics were seized during raids on two CBD stores and one Western Sydney warehouse last Friday.

The raids follow a Fair Trading investigation into consumer complaints, including one woman who received burns to her face after using the dodgy goods.

NSW Fair Trading Minister Matthew Mason-Cox said it's not always easy to spot a fake, so shoppers should scrutinise the labelling and always buy from a reputable trader.

"Others reported that it was not until the product packaging had been opened that it became obvious they had purchased a fake due to a different colour and consistency to the genuine article," he said.

"The cosmetic industry is a billion dollar market and our concern is that consumers can be misled into paying top dollar for fake and inferior products," he said.

Mr Mason-Cox said counterfeit peddlers can face fines of up to $220,000 for individuals and $1.1 million for corporations.

In May, a Paddy's Markets trader, Michael Lam, was ordered to pay fines and costs of $17,180 by Parramatta Local Court for selling counterfeit football clothing.