Black plastics may contain toxic compounds that can leach into food, experts say

Certain products made from black plastic — like the kind found in takeout containers, coffee lids and even kitchen utensils — is coming under fire by experts because of a recent study that found a lack of regulation around recycling is causing toxic chemicals to show up in household plastics.

In a study published in the journal Chemosphere in October, researchers from the U.S. and the Netherlands found brominated fire retardants (BFR) used to strengthen plastics for electronics in household products made with recycled black plastics in the U.S.

Fire retardants — including toxic, regulated compounds — were found in roughly 85 per cent of products analyzed by the study's researchers. The items tested include kitchen utensils, food trays and even children's toys.

"In many cases, when we come across black plastics in our kitchen, they are made from recycled electronic components that include cell phones, old computers and laptops that are not intended for human food applications," said Tizazu Mekonnen, a University of Waterloo chemical engineering professor who was not involved in the study. 

The study estimated that using contaminated kitchen utensils contributed to the ingestion of 34,700 nanograms of fire retardant decabromodiphenyl ether per day. The U.S. Environmental Protection Agency's reference dose — or recommended limit — of 42,000 nanograms per day for an average 60 kilogram adult. 

The study examined the amount of fire retardants in items made with black plastic, but not humans. 

Mekonnen and other experts say that we should minimize the use of black plastic in our homes and kitchens to prevent plastic-related chemicals from possibly harming our health. 

Black plastic is coloured using a substance called carbon black, according to Western University biochemist Elizabeth Gillies. 

"This is essentially soot that is produced by the incomplete combustion of different materials like coal or petroleum products, or vegetable matter," she said.

Concerns arise, however, when recycled plastic from electronics end up in household and kitchen plastics. 

That's because plastics in electronics contain compounds — like brominated fire retardants that help prevent the plastic from melting under high heat — which may be harmful when ingested in significant concentrations. 

Physicians like Dr. Sehjal Bhargava say consuming food contaminated by the toxic compounds found in black plastic may contribute to serious health concerns, including cancer and fertility issues. 

"The health impacts are not yet fully understood, but the evidence that's emerging is not good news," said Bhargava, an Ontario family physician and public health and medical resident at the University of Ottawa who sits on the board of the Canadian Association of Physicians for the Environment.

Mekonnen says the risk of harmful health effects is increased when black plastic products are heated up, like when containers are microwaved, or when utensils are used on a grill or stove.