(CBS Local) — Despite concerning medical findings, many people still microwave their food in plastic containers. A new warning from the Cleveland Clinic is now urging people to ditch the containers, even if they are labeled “microwave-safe.”

Lindsey Malone, dietitian and manager of nutrition, at the Ohio hospital says the materials in plastic containers can contaminate other objects when heated. “With plastic, you can have high temperatures from the microwave or the dishwasher, those plastics can become unstable and components can get into your food,” Malone told Cleveland 19 News.

Physicians claim the danger of plastic contamination has been linked to increases a number of illnesses including cancer. While some containers are marked safe for the microwave, Malone warns that people should look for the “BPA free” label on plastics. BPA, or bisphenol A, is an industrial chemical used in manufacturing plastic items. Exposure to BPA has reportedly been linked to health problems in the brain, prostate glands of children, and an increase in blood pressure.

“You want to look on the container, and see if it has a microwave safe label. That is regulated by the FDA and tested. If it doesn’t, I definitely would not put things in the microwave,” Malone said. She adds that BPA free containers may be safer but there is still a risk when heating them.

The FDA recommends glass, porcelain, or stainless steel containers as an alternative for heating foods instead of using plastics.