Leftover takeaway? Please don’t reheat that plastic container

You forget to bring your water bottle to the airport, so you buy a plastic one and keep refilling it. Or you order takeaway for dinner and save the plastic container to pack your lunch the next day.

Reuse is one of the core rules of sustainability. But should you be reusing these single-use plastics? Experts say no.

Black plastic poses specific dangers, says Megan Liu, a science and policy manager at Toxic-Free Future.Credit: Getty Images

As research on chemical exposure from plastics pollution has advanced in the last decade, scientists are “now finding it in pretty much every kind of food you can look at,” says Sherri Mason, plastic pollution researcher and director of Project NePTWNE at Gannon University.

“There is a real significant potential human health impact that is associated with reusing plastics, whether you’re talking about beverages or food,” Mason says. Children and people of reproductive age face the highest risks, she adds.

“We really believe that reducing plastics reuse is the best possible approach,” says Megan Liu, science and policy manager at the advocacy group Toxic-Free Future.

Though plastic is found throughout our homes and everyday lives, there are a few ways you can reduce your exposure to potentially harmful chemicals. Here’s what you should know about reusing single-use plastics.

The risk from single-use plastics

Single-use plastics leach chemicals and shed microplastics into your environment. Though studies have not directly compared single-use and reusable plastic, experts say they are more concerned about single-use plastic because of how they’re made.

“I like to compare it to our skin constantly shedding skin cells,” Mason says.

Scientists have shown that plastic water bottles shed hundreds of thousands of plastic particles into the water.Credit: Getty Images

That means a single-use plastic water bottle sheds micro- and nano-plastics into your water when you refill it, and a takeaway container or frozen meal tray sheds these particles into your food.

Scientists have shown that plastic water bottles shed hundreds of thousands of plastic particles into the water, many of which are nano-plastics, which measure less than one micrometer, less than one-seventieth the width of a human hair.

There are about 16,000 chemicals found in plastic, Mason says, over 4200 of which are considered “highly hazardous”.

Because many chemicals are not bound to the plastic, those compounds can migrate into your food or drink. Known carcinogens like styrene have also been found in plastics.

Chemical exposure increases if plastic is heated, typically in a microwave, a dishwasher or even by placing hot food in a takeout container. When heat is applied, molecules move faster, meaning it could be easier for some of these particles to make their way into your food.

The danger of heating your plastic also applies to reusable plastic, like sturdier plastic water bottles, baby bottles and plastic storage containers, according to Judith Enck, president of Beyond Plastics.

Black plastic poses specific dangers, says Liu, who published a study last month on the topic. The research found that black plastic in sushi trays, cooking utensils and other objects contain high levels of flame retardants. These toxic chemicals have been linked to hormone disruption, reproductive complications and elevated cancer risk.

“What we found is that they could be contaminated with flame retardants, likely as a result of electronic waste recycling,” Liu says.

The International Bottled Water Association said that it does not recommend reusing single-use beverage containers because of the “potential health risks due to bacteria growth and contamination”.

How to use plastic in your home

Concerns with chemicals and microplastics primarily apply to food and beverages, experts say, because you are swallowing them. Reusing single-use plastics like grocery bags is not a major concern, they add.

The impact of microplastics probably depends on how old you are, Mason says, with her biggest concern being “kids and people of reproductive age” given the link with declines in fertility and the disproportionate presence of microplastics in young children.

The most important thing you should do is avoid subjecting your plastic to heat, experts agree.

“A pretty hard-and-fast rule is to never microwave plastic,” Enck says. “And there’s also a recommendation not to put plastic into the dishwasher if it’s on a hot cycle.”

If you order takeout, it’s best to transfer the food to a non-plastic dish as soon as possible, and you should use a plate when microwaving your food.

Glass and metal water bottles are safer than reusable plastic ones, so make sure to bring them along when you travel or leave your house for errands.

Although it would be ideal to switch out all the plastic found in your kitchen, Liu recommends focusing on your cooking utensils and opting for glass or metal storage containers. Cleaning helps, too, she adds.

“Keeping your home well-ventilated and making sure to dust, mop and vacuum on a regular basis can also help reduce the buildup of harmful chemicals in your environment.”

The Washington Post

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