Studies indicate that this plastic is safe for one-time use. As a precaution, however, these bottles should not be reused or heated. Common usage of PET/PETE includes bottles for water, cooking oil and soft drinks.

Limit how often you refill containers made of HDPE. It can be recycled one time into new secondary products such as fabric, carpet or plastic lumber. Common usage of HDPE includes juice bottles, containers for detergent, shampoo and motor oil, and toys.

The manufacture of PVC creates dioxin, a potent carcinogen that contaminates humans, animals and the environment. PVC may also contain phthalates to soften it. These hormone disrupting chemicals have been linked to male reproductive problems and birth defects.

LDPE is one of the safer plastics. Common usage of LDPE includes grocery store bags, plastic wrap for household use and garbage bags. Try to reduce waste by bringing a reusable bag instead.

PP is one of the safer plastics, but be sure to recycle wherever possible. Common usage of PP includes ice cream and yogurt containers, drinking straws, syrup bottles, salad bar containers and diapers.

PS can leach styrene, a known neurotoxin with other harmful health effects. Try to avoid using products housed in PS-manufactured containers, this includes styrofoam. Common usage of PS includes coffee cups and meat trays, and opaque plastic spoons and forks.

This category is a mixed bag, which needs further investigation. It includes polycarbonate, a plastic made from BPA, a harmful synthetic estrogen. Manufacturers use polycarbonate to make large 1-litre water bottles, sports bottles, clear plastic cutlery or the lining of metal food cans. It also includes some new, compostable green plastics, such as those made from corn, potatoes, rice or tapioca.