According to Morse, it depends on the brand. “Many companies are now focusing on removing harmful chemicals [from plastic containers]. On the bottom of food containers, you’ll find a number printed somewhere that will be between 1 and 7, which indicates what the plastic is made of. Plastics with number 1, 2, 4, and 5 are generally considered safe to be used with food. Numbers 3, 6, and 7 are generally considered unsafe or higher risk of contaminating food and should be avoided for use as storage containers.”