"Anytime you use these products, make sure that you have read the instructions on the box about whether it's appropriate for microwave use," said Dr. Cyrus Rangan, a toxicologist with the California Poison Control System.
Pay attention to the triangle symbols with numbers located on the bottom of plastic products. Many people have no idea what they mean. The numbers in the triangle range from 1 to 7.
"Some of them designate whether or not it's safe to use a product more than once. So certain products, because of their designation, mean only use this product once," said Rangan.
Most water bottles are marked with a "1," which means single-use and you can recycle it. If your water bottle has a "3" or "5" on it, most places in the U.S. won't accept it for recycling.
For example, one container I had was marked with a "5," indicating it's made of polypropylene. It is safe for reuse. As far recycling, you'll have to check with your local curbside recycling program.
If there's a "2," it's probably a household cleaner, juice, butter tub or shampoo bottle. They all can be recycled.
Containers with a "3" are made out of vinyl; they're also recyclable, but don't use them for food.
A "4" is found on plastic garment bags and squeezable bottles; they're reusable. A "6" is mainly found on Styrofoam.
"In general, you should never microwave Styrofoam," said Rangan.
Number "7" was designed as a catch-all category for other plastics, such as polycarbonates. Reuse and recycle standards will vary, but experts say understanding the classifications will help minimize health problems and disposal issues.