What to Look For

Plastics are classified by their "resin identification code"—a number from #1 to #7 that represents a different type of resin. That number is usually imprinted on the bottom of your container; flip it upside down, and you'll see a recycling triangle with the number in the middle.

Here's a quick breakdown of plastic resin types:

#1 polyethylene terephthalate (PET or PETE)
Examples: Disposable soft drink and water bottles

#2 high density polyethylene (HDPE)/
Examples: Milk jugs, liquid detergent bottles, shampoo bottles

#3 polyvinyl chloride (V or PVC)
Examples: Meat wrap, cooking oil bottles, plumbing pipes

#4 low density polyethylene (LDPE)
Examples: Cling wrap, grocery bags, sandwich bags

#5 polypropylene (PP)
Examples: Cloudy plastic water bottles, yogurt cups/tubs

#6 polystyrene (PS)
Examples: Disposable coffee cups, clam-shell take-out containers

#7 other (plastics invented after 1987; includes polycarbonate, or PC, and polylactide, or PLA, plastics made from renewable resources as well as newer plastics labeled "BPA-Free")
Examples: Baby bottles, some reusable water bottles, stain-resistant food-storage containers

What To Buy:

#2 HDPE, #4 LDPE and #5 PP: These three types of plastic are your best choices. They transmit no known chemicals into your food and they're generally recyclable; #2 is very commonly accepted by municipal recycling programs, but you may have a more difficult time finding someone to recycle your #4 and #5 containers.

#1 PET: Fine for single use and widely accepted by municipal recyclers; avoid reusing #1 water and soda bottles, as they're hard to clean, and because plastic is porous, these bottles absorb flavors and bacteria that you can't get rid of.

PLA: plastics made from renewable resources such as corn, potatoes and sugar cane and anything else with a high starch content; although you can't recycle these plant-based plastics, you can compost them in a municipal composter or in your backyard compost heap.

Plastics to Avoid:

#3 PVC: Used frequently in cling wraps for meat, PVC contains softeners called phthalates that interfere with hormonal development, and its manufacture and incineration release dioxin, a potent carcinogen and hormone disruptor.

#6 PS: Polystyrene-foam cups and clear plastic take-out containers can leach styrene, a possible human carcinogen, into food.

#7 PC: The only plastic made with bisphenol A, polycarbonate is used in baby bottles, 5-gallon water-cooler bottles and the epoxy linings of tin food cans. Bisphenol A has been linked to a wide variety of problems such as heart disease and obesity.

Shopping Tips

• Plastics are classified by their "resin identification code"—a number from #1 to #7 that represents a different type of resin. That number is usually imprinted on the bottom of your container; flip it upside down, and you'll see a recycling triangle with the number in the middle.

• When purchasing cling-wrapped food from the supermarket or deli, slice off a thin layer where the food came into contact with the plastic and store the rest in a glass or ceramic container or wrap it in non-PVC cling wrap.

Usage Tips

• Avoid storing fatty foods, such as meat and cheese, in plastic containers or plastic wrap.

• Hand-wash reusable containers gently with a nonabrasive soap; dishwashers and harsh detergents can scratch plastic, making hospitable homes for bacteria.

• A "microwave-safe" or "microwavable" label on a plastic container only means that it shouldn't melt, crack or fall apart when used in the microwave. The label is no guarantee that containers don't leach chemicals into foods when heated. Use glass or ceramic containers instead.