It's worth avoiding the following plastics when you can. You can identify a plastic by looking at the recycling code number that appears inside a triangle at the bottom of many containers.
Polyvinyl chloride (PVC) can leach phthalates, known male reproductive toxicants. It can be identified by code 3. One way to avoid it in the kitchen is by choosing plastic wrap made from polyethylene rather than PVC. If a box is not labeled, find a brand that is or call the manufacturer.
Polystyrene is used in Styrofoam products. It may leach styrene (a neurotoxin) when it comes into contact with hot, acidic, or fatty foods. It's marked with recycling code 6.
Polycarbonate can leach bisphenol-A (BPA), an endocrine disruptor associated with a long list of health concerns. Baby bottles, "sippy" cups, 5-gallon water jugs, and reusable beverage bottles are typically made out of this plastic. Products may be marked with recycling code 7 (also includes any plastic that doesn't fit into the 1 to 6 recycling code categories) and/or the letters "PC."
In response to the widespread concerns about BPA, baby bottles and other items made from alternative materials are springing up. Experts say stainless steel is your best bet for reusable water bottles right now. ThinkSport and Klean Kanteen are two widely available brands.
The following plastics are considered safest for food storage. Glass and stainless steel are also good options.
Polyethylene terephthalate ethylene (PETE), code 1.
High-density polyethylene (HDPE), code 2.
Low-density polyethylene (LDPE), code 4.
Polypropylene (PP), code 5.
Here are some tips for using all plastics safely: