Microwaves have become a must-have in most modern kitchens. From warming a meal to heating up a cup of tea, microwaves seem indispensable. I guess we could peg that to our fast-paced lifestyles and technology that seems to push us to look for ways to better our lives.
It is a given that when any appliance is in good condition, it is safe for use. The same goes for a microwave. That said, we need to take care of the containers we use in the microwave regardless of its safe condition. While they may be convenient to use owing to their availability, some plastics may pose health risks.
How microwaves work
According to homeguides.sfgate.com, microwave ovens use high frequency waves of electromagnetic radiation to heat and cook foods and beverages. These microwaves of energy cause the molecules within foods and liquids to vibrate rapidly, producing heat. Many glass or plastic containers do not absorb enough microwaves to become hot during cooking. In fact, “microwave safe” glass, plastic or ceramic cookware allows most of the microwave energy to pass safely through to the food within.
In contrast, metal objects reflect the microwave energy back within the oven cavity and may spark a potentially damaging electrical discharge.
Angella Nalukonge, a nutritionist, says: “First of all, I would advise people to limit their use of microwave ovens as much as they can. When it comes to using plastics whether in form of containers, wraps or films, most of them are not safe because they contain chemicals called plasticisers which may be transferred to the food.” She adds that these chemicals are thought to cause cancer or disrupt the hormonal system in the body.
“Some plastic containers are however safe for use and these are labelled, ‘microwave safe’,” she says.
David Walugembe, a nutritionist, says plastics are not safe to be used in microwaves because when they are exposed to heat, bisphenol A, (BPA), a hormone is released. “This endocrine disrupting chemical leaches into the food and higher doses can result into heart disease and impotence,” he explains.
Health.harvard.edu, an online portal also cites another endocrine disrupting chemical found in plastics called phthalates. It states that these substances mimic human hormones, and not for the good. “When food is wrapped in plastic or placed in a plastic container and microwaved, BPA and phthalates may leak into the food. Any migration is likely to be greater with fatty foods such as meats and cheeses than with other foods,” the site adds.
The nutritionists unanimously say, “Before any heating is done, it is safe to look out for materials such as glass and ceramics because they are safe and recommended.”
• Do not use cling film while microwaving because it may melt. In place of cling film, a container that fits well over the plate or bowl are a better alternative.
• Most, if not all takeout containers (foil containers) or jars that hold yoghurt, and foods such as mayonnaise, and mustard are not safe to use in microwaves.
• Microwavable takeout trays are meant for one-time use only.
• Never microwave foods in plastic bags got from grocery stores.