Metal travel mugs can be dangerous because they are made mainly of metal.
You may want to reconsider putting a travel flask or mug in the microwave if you own one. Pour your drink into a container that is microwave safe if you want to warm up a hot drink. Most travel mugs, however, are made of stainless steel which is not microwave safe.
Why? When the microwave emits waves, they bounce off of the stainless steel, and instead, around the appliance. It could cause serious damage to your microwave, and even ignite a fire. You should never put anything metal into a microwave, unless it’s specifically allowed by the instructions.
Plastic wrap releases harmful chemicals upon heating
Many people wrap their leftovers with plastic wrap in order to keep them in the fridge. You must unwrap the food first before putting it in the microwavable. Plastic wrap, another single-use material that is susceptible to releasing harmful chemicals when exposed to microwave radio waves, is a good example.
Microwaving plastic wrap can release chemicals such as benzene and toluene. These can be inhaled or, even worse, end up in food. You don’t want to breathe or eat these chemicals, so unwrap leftovers first.
