Trasande says there are "safe and simple" steps families can take to limit exposure to phthalates. These include not microwaving food in plastic containers or covered by plastic wrap, and washing plastic food containers by hand instead of putting them in the dishwasher, where harsh chemicals can lead to increased leaching of plasticizers into food. He says people can also avoid using plastic containers labeled on the bottom with the numbers 3, 6 or 7 (inside the recycle symbol), in which chemicals such as phthalates are used.