Plastic #1: This is safe but should not be re-used due to the porous surface that allows bacteria to accumulate. Most disposable soda and water bottles are made of 1 plastic, and it’s usually clear.

Plastic #2: Most milk jugs, detergent bottles, juice bottles, butter tubs, and toiletries bottles are made of this. It’s usually opaque. This plastic is considered safer and has a lower risk of leaching.

Plastic #3: This is used to make food wrap and cooking oil containers. There are phthalates in this material–softening chemicals that interfere with hormonal development. Minimize use of this plastic around food as much as possible. Never cook using food wrap, especially in a microwave.

Plastic #4: This is used to make grocery bags, some food wraps, squeezable bottles, and bread bags. This plastic is considered safer.

Plastic #5: Yogurt cups and similar wide-necked containers are often made from it, as well as water bottles with a cloudy finish. You’ll also find it in medicine bottles, ketchup and syrup bottles, and straws. This plastic is also considered safer.

Plastic #6: This is Styrofoam, from which disposable containers and packaging are made. You’ll also find it in disposable plates and cups. Evidence is increasingly suggesting that this type of plastic leaches potentially toxic chemicals.

Plastic #7: This number basically means “everything else,” including modern plastics used in anything from iPods to computer cases. It also includes some baby bottles and food storage containers. Should be avoided since you don’t know what could be in it.