Plastic by the Numbers, Which to Avoid and Why

Plastics make up 11.7 percent of U.S. waste and are among the least-recycled items. The manufacture of plastics can involve the emission of toxic substances into the atmosphere. And when plastics are incinerated, toxics such as lead and chlorine are released.

Chemists have spun hundreds of kinds of plastics, but most common containers fall in one of seven categories. To help recycling centers sort landfill-bound plastics from those than can find life in new products, the Society of the Plastics Industry developed the numeric system to identify the type of plastic resins used.

• #1, PETE or PET (Polyethylene Terephthalate) -- Used for clear beverage bottles. Widely recyclable. Shown to leach phthalates (known hormone disrupter) when reused or stored for long periods.
• #2, HDPE (High-Density Polyethylene) -- Used for colored or cloudy bottles and jugs, yogurt containers, and other tubs. Widely recyclable, but consumers need to verify with local recyclers whether tubs and bottles (which are made differently and can’t be recycled together) need to be separated. Generally considered safe, with some precautions.
• #3, PVC (Polyvinyl Chloride) -- Used in some cling wrap and bottles, as well as pipes and other construction materials. Not widely recyclable; recommended to avoid because it can leach toxins into food and is an environmental problem throughout its lifecycle.
• #4, LDPE (Low-Density Polyethylene) -- Used for garbage bags, food storage bags, and some cling wrap and bottles. Not widely recyclable; generally considered safe, with some precautions.
• #5, PP (Polypropylene) -- Used in butter tubs, some baby bottles, and other rigid containers. Not widely recycled; generally considered safe.
• #6, PS (Polystyrene) -- Used in foam trays, takeout containers, coolers, egg cartons, and packing peanuts. Not widely recyclable, although many packing and shipping stores accept packing peanuts for reuse. Recommended to avoid because styrene may leach into food and beverages.
• #7, Other (Includes Polycarbonate and mixed materials) -- Used in five-gallon water bottles, some baby bottles, and some liners of metal cans. Not widely recyclable; recommended to avoid because bisphenol-A can leach from polycarbonate into food and beverages.