Plastics Q&A

Some of the containers in my kitchen do not have a recycling number on them. How do I know whether these plastics are safe? Why do some companies not put numbers on their products?

The best way to find out is to call the manufacturer. The "resin identification code"—the number that appears in the recycling triangle—isn't actually required by federal law and doesn't appear on every plastic product you buy. It's a voluntary system aimed primarily at helping recycling centers identify and sort various products. Some states require companies to put resin codes on bottles, but they aren't required on products that aren't easy to recycle, such as bowls, dishes, toys or bottle caps.

Do the recycling arrows with the code number on the bottom of plastics apply only to North America or are they international?

The resin identification numbers (we've defined them in our Plastic Containers Buying Guide) are used all over the world. So no matter where you are, you'll know whether you can recycle your plastic bottle or cup.

Which numbers of plastic containers contain bisphenol A (BPA)?

The only kind of plastic food-storage containers that contain BPA are those made with polycarbonate, which is indicated by #7 PC in the recycling triangle on the bottom.

The Brita filter system we use is a plastic carafe style, which does not indicate what type of plastic it is. Do I assume that it is made with the number 7 plastic and may leach BPA into the water?

Brita pitchers, according to a customer representative at the company, are not made from polycarbonate plastics and therefore don't contain BPA. The pitchers are made with either NAS (a styrene-based plastic with a very long chemical name) or styrene acrylonitrile (SAN). Brita has had its pitchers independently tested by the National Sanitation Foundation to ensure that they don't leach styrene, a probable human carcinogen, and the FDA has also tested these resins and found them to be leach-free. Read more about Brita pitchers here.

I was wondering about the safety of cooking food in Ziploc Zip 'n Steam bags and in Birds Eye, Green Giant, and other manufacturers' plastic containers. Is this a plastic that is not safe or can put off poisons in our food when it is cooked?

We weren't able to get the exact make-up of the Birds Eye and Green Giant bags, but company reps from Ziploc informed us that their Zip 'n Steam bags are made with polypropylene (#5) and polyethylene (PET, #1) plastics. Both are considered safer plastic resins and shouldn't leach any hazardous chemicals into your food. However, we generally don't recommend microwaving food in plastic as a precautionary measure (these bags, given that they're only used once, shouldn't cause problems, but if you accidentally overdo it and leave the vegetables cooking for too long, the bags might overheat and melt). It's better to microwave food in glass or ceramic containers or to steam vegetables in a pot over the stove rather than in a plastic bag. Besides, if you buy fresh vegetables and steam them over the stove, you'll save the plastic-bag waste.

Is it safe to reuse #4 food storage bags? We have been washing them with warm water and soap and reusing them in order to reduce waste.

It's safe to reuse them until they start to get cloudy. Cloudiness is a sign of deterioration, and even though #4 plastics aren't known to contain any hazardous chemicals, deteriorated plastic bags may transmit chemicals with unknown side effects into your food. They also start to absorb odors and flavors that make your food less tasty.

In the past I have reused typical bottled water containers to take to the spa every day, freezing them to have cold water. Now I've read this is not a good thing. Is that because water is sitting in the bottle for long periods?

The main reason we recommend against this has to do with bacterial contamination. The #1 PET plastic used in these bottles is porous, and these bottles absorb flavors and bacteria that you can't get rid of. There is also a concern of the heavy metal antimony, which can trigger diarrhea and upset stomachs, leaching out of #1 bottles after they've been used for a very long time (usually more than six months).

I want to replace my reusable plastic bottle with a stainless steel Klean Kanteen. However, I found this product is produced in China. Are you aware of this, and if so, is it a concern? If quality control is lacking, this small factory may use low-grade stainless steel exposing nickel and possibly lead.

There's no need to worry about stainless steel made in China. Lead contamination isn't a concern with stainless steel, regardless of where it's made, because stainless steel contains steel, chromium and nickel only—no lead. To ensure product safety, Klean Kanteen tests shipments of its bottles every three months to make sure they're free of nickel (which may trigger allergic reactions), chromium (high levels of which can cause kidney or liver damage) and manganese (linked to nervous-system problems). Manganese isn't usually found in the kind of stainless steel Klean Kanteen uses, but it is used in other types, so their tests for it are mainly precautionary.

I understand that the plastic water bottles in stores leach a carcinogen.

Based on current science, the plastic water bottles, soda and juice bottles, and milk jugs on store shelves don't contain any cancer-causing chemicals. There have been some reports in the media that bisphenol A (or BPA), the chemical used to make polycarbonate water bottles and water-cooler jugs, causes cancer, but so far, there's no scientific evidence to support that. BPA does, however, interfere with hormones. A just-released study found that it suppresses levels of the hormone needed to protect people from heart attacks and Type II diabetes—so drink your water from the tap, not a water cooler or polycarbonate bottle.

I use 4-gallon plastic water bottles for my standing refrigerated water cooler. On the bottom of the bottle there is a triangle with a # 3 in it. Is it okay to use these?

Without sounding like an alarmist, replace these bottles post haste! The #3 indicates that the bottle is made with polyvinyl chloride, which can leach hormone-disrupting phthalates and possibly lead into your water.

Plastic bags are everywhere—it's not just shopping bags, but the bags my organic lettuce comes in, my string cheese, and on and on! I can only find a place that recycles #2 and #4 bags, along with dry-cleaning and newspaper bags. There are so many other plastic bags out there and it makes me sick to have to throw them out. Is there another option?

Thanks to growing concern about the environmental ills wrought by errant plastic bags, many cities are banning them or, at the very least, requiring stores to recycle them—but usually those requirements pertain to shopping bags, not all the other plastic films used to package our products. You can recycle various types of plastic bags and wraps at Whole Foods Markets and a growing number of national chain stores. But be aware that just like your curbside recycling program, these collections are limited by what they can recycle regionally. Call the store ahead of time to see which types of plastic bags, wraps and films they accept; some take frozen-vegetable bags and cling wraps as well as plastic produce and grocery bags, while others only take grocery bags. When you do take your stuff in to be recycled, just make sure it's clean and dry, or it could ruin an entire bin's worth of recyclable materials.