Microwave-Safe Plastics May Not Be Safe: The Health Risks of Microplastics from Food Containers

Kazi Albab Hussain, a graduate student studying environmental nanotechnology, became concerned about plastic exposure when he became a new father. He decided to investigate how much plastic was being released from the baby food containers he used. His study, published in Environmental Science & Technology, found that when microwaved, these containers released millions of microplastic and nanoplastic particles, posing potential health risks.

Plastics are composed of polymers and chemical additives, and microwaving can cause them to release microplastics and nanoplastics due to heat and hydrolysis. These particles can enter the body, coating themselves with proteins and bypassing the immune system. They can also carry a community of microbes into the body, potentially leading to health issues.

While the exact health effects of plastic exposure remain uncertain, studies suggest that these particles can be toxic, especially nanoplastics. They can interfere with hormones and disrupt bodily functions, making babies particularly vulnerable. To assess plastic exposure in baby food, Hussain’s team tested three types of containers and found that microwaving released the most microplastics and nanoplastics.

The study revealed that hotter storage temperatures led to more plastic particle leakage. Microwaving, in particular, resulted in the highest release of microplastics and nanoplastics. When kidney cells were exposed to these particles, a significant portion died, indicating potential health risks. While the study used higher concentrations of plastic particles than real-life exposure, the long-term effects of cumulative plastic exposure remain unknown and warrant further investigation. Additionally, chemical additives from plastics may also pose health risks.

Experts recommend avoiding microwaving plastic containers, especially for parents and pregnant individuals. They emphasize the need for the FDA to take a more proactive role in regulating microwave-safe plastics. There is growing consensus that labeling plastics as “microwavable” may not ensure safety.

Reducing plastic exposure will require government action and corporate responsibility. Third-party certification programs connecting food companies with independent scientists could help ensure product safety. On an individual level, opting for glass or stainless steel containers and avoiding pouring hot liquids into plastic containers can reduce plastic exposure. Scientists should continue research to understand specific particle release from plastics and inform regulations effectively. 

Dr. Permuth offers these helpful tips when using the microwave:

• Transfer food to glass or ceramic containers labeled for microwave oven usage if you are concerned about using plastic containers or wraps in the microwave.
• Alternatives to plastic include wax paper, kitchen parchment paper, or white paper towels that fit over a plate or bowl.
• Most takeaway containers, water bottles, plastic storage bags, and plastic tubs containing margarine, yogurt, whipped topping, and foods such as cream cheese, mayonnaise, and mustard are not microwave-safe.
• Before microwaving food, leave the lid slightly open or lift the edge of the cover to allow ventilation.