Nine popular Australian skincare products have been pulled from shelves over safety concerns linked to a banned ingredient.

Plastic microbeads -- tiny plastic particles outlawed by the federal government -- were found in products unlawfully sold in NSW that were produced by six companies.

The NSW Environment Protection Authority (EPA) has issued Compliance Notices to the companies since April 2024, ordering the products' withdrawal across the state.

Plastic microbeads were once widely used in cosmetics and personal care products to add texture, exfoliate skin, or extend shelf life.

They were banned in NSW from November 1, 2022, and are also prohibited in Queensland, Western Australia and the ACT.

EPA CEO Tony Chappel said the beads don't readily break down in the environment and pose ecological risks.

"Microbeads don't belong in skincare or our waterways -- they can threaten marine life and people's health," Chappel said.

Because wastewater systems can't capture most microbeads, they often end up contaminating rivers, creeks, lakes and oceans, EPA said.

Once released, they can absorb pollutants and enter the food chain.

The EPA said the companies promptly removed affected stock from shelves after being notified.

Failing to comply with a Compliance Notice can attract fines of up to $550,000, plus $55,000 for each additional day the offence continues.

The EPA is one of the few regulators worldwide to have taken enforcement action against the use of plastic microbeads in personal care products.