Plastics In the Home: Recycling and Cooking

The past few generations have lived through the age of plastic. They've become such an ubiquitous part of our lives that they've even become the subject of humor. Environment jokes about plastics, for example, have been around at least as long as The Graduate ushered in the future with one word, plastic.

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For practical reasons, plastics in the home provides some general recycling and cooking tips. While some plastic recycling takes place, the amount in the waste stream continues to pile up. Additionally, we cook with plastics and hear warnings that plastics leech dangerous chemicals. Here's the latest.

Types of Plastics

In an attempt to bring order to plastics classification for recycling purposes, the Society of the Plastics Industry (SPI) devised some voluntary codes in 1988. These codes (numbered recycling arrows), commonly called SPI codes, get stamped or labeled on most plastic products. The numbers within the recycling arrows refer to different types of plastic resins.

The addition of corn based plastic, PLA, into the plastic bottle and wrapping industries represents the only significant update to plastics typing over the past twenty years.

Absent federal plastic labeling regulations, a bit of inconsistent labeling might be expected industry wide. As a general rule of thumb, use of SPI codes across the plastic industry remains a fairly standard practice. A brief description of each SPI plastic type follows.

  • PET (polyethylene terephthalate): plastic soft drink bottles, water bottles, beer bottles, mouthwash bottles and many more
  • HDPE (high density polyethylene): milk bottles, detergent bottles, oil bottles, toys, plastic bags
  • PVC (polyvinyl chloride): food wrap, vegetable oil bottles, blister packaging
  • LDPE (low density polyethylene): bread bags, frozen food bags, squeezable bottles, fiber, tote bags, bottles, clothing, furniture, carpet, shrink-wrap, garment bags
  • PP (polypropylene): margarine and yogurt containers, caps for containers, wrapping to replace cellophane
  • PS (polystyrene): egg cartons, fast food trays, disposable plastic silverware
  • Other: This code indicates that the item is made with a resin other than the six listed above, or a combination of different resins.

The pie chart at the top of the page compares the amount of the different plastic types in the 2010 municipal waste stream. The common beverage container plastics, PET and HDPE, compose approximately 30% of the 2010 plastic waste stream. Packaging materials, primarily the low density polyethylene materials compose another 23.9% of the waste stream.

Taken together, the statistics tell us that plastic beverage containers and plastic food packaging make up over fifty percent of the total plastic waste stream.

The recent addition of PLA plastic waste statistics provides one additional chart note. Currently PLA constitutes .2% of the entire plastic waste stream.

Total PLA waste may or may not be sufficient to contaminate already established plastic recycling waste streams. Apart from that issue, the small amount of current PLA production provides little insight into potential long term PLA production trends.

Plastic recycling discussions get a bit more detailed about the types of plastics in the waste and recovery streams.

The statistics presented in the plastic recycling article follow the industry standard three category organizing framework, which distinguishes between durable, nondurable and container plastic types.

Plastic Recycling

pie chart comparing the total amount of water and pop bottles (PET) and milk jug bottles in the 2010 municipal waste stream

The existence of plastic waste caught up in ocean currents causing harm to wildlife, speaks to the importance of a continued global discussion regarding the use and disposal of commercial plastics.

Aggregate plastic production and management trends in the United States read fairly easy. Recent EPA plastic recycling statistics show an increase from the baseline zero plastic recycling in 1970, to the 2010 high of 8.3% of total waste plastic recycled.

Generally plastic recycling rates tend to lag behind other material recycling rates, due in part to plastic's multiple uses, not all of which easily lend themselves to recycling.

Plastic in and the Microwave

pie chart comparing American use of the microwave oven

According to the Residential Energy Consumption Survey (RECS 2009), we've become a nation of microwave users. An estimated 109 million American households, of the estimated 113 million American households, contained a microwave oven.

The pie chart shows that over one-half of Americans (52.8%) use a microwave to to prepare from one-half to all of the household meals and snacks.

The use of plastic wrap remains a popular practice for packaging foods for microwave use. Over the course of the past few decades, information regarding the dangers of microwaving plastic continues to arise. The Food and Drug Administration recently posted a response to the issue of plastics in the microwave, slightly edited and reprinted below.

Under the food additive provisions of the Federal Food, Drug, and Cosmetic Act, new substances used to make plastics for food use are classified as "food contact substances."

They must be found safe for their intended use before they can be marketed.

It's true that substances used to make plastics can leach into food

says Edward Machuga, Ph.D., a consumer safety officer in the FDA's Center for Food Safety and Applied Nutrition...Microwave-safe plastic wrap should be placed loosely over food so that steam can escape, and should not directly touch your food..

Always read directions, but generally, microwave-safe plastic wraps, wax paper, cooking bags, parchment paper, and white microwave-safe paper towels are safe to use. Covering food helps protect against contamination, keeps moisture in, and allows food to cook evenly. Never use plastic storage bags, grocery bags, newspapers, or aluminum foil in the microwave.

Source Food and Drug Administration (FDA)