Decoding Plastic Recycling Numbers

Try visiting the grocery store without buying any plastic. Just about the only things you can purchase without accumulating some from of plastic packaging are fruits and vegetables (but only if they are big enough not to warrant a plastic container), and dry items such as flour, sugar and salt. It seems we're a society dependent on plastic—and all that plastic is adding up.

Plastics accounted for 31 million tons of municipal solid waste in 2007, according to the U.S. Environmental Protection Agency (EPA), of which 14 million tons were containers and packaging. According to the EPA, plastics production has grown steadily since the 1960s and continues to grow each year.

But plastics, which are made from oil mixed with other chemicals, are increasingly drawing fire from researchers and the general public over the health effects of toxic ingredients such as bisphenol A (BPA) and phthalates, and the environmental impact of waste that can take hundreds of years to break down.

According to the United Nations Environment Programme, it is estimated there are more than 13,000 pieces of plastic floating on every square kilometer of surface ocean area.

Oceanographers have identified a "plastic soup" of garbage floating just below the surface of the water in the Pacific Ocean, stretching from mid-way between San Francisco and Hawaii to the waters off of Japan.

For now, it ultimately comes down to personal choice. The recycling numbers on the bottom of plastic products identify the type of plastic the product is made with. Each plastic is composed of different chemicals, and some plastics are more likely to leech volatile organic compounds (VOCs) and other toxins while others are more stable. Using the recycling numbers, you can make informed decisions about what plastics you feel comfortable using, and which ones you'd rather just leave on store shelves.

#1 PTE (also PETE): polyethylene terephthalate

PTE is a lightweight plastic that can be made semi-rigid or rigid, so it has many applications. It is most commonly manufactured as a fiber (polyester), with plastic bottles accounting for almost all of the remaining global production. It is also used for food trays.


  • PET contains DEHA—di-(2-ethylhexyl) adipate—which is an endocrine disruptor. The EPA classifies DEHA as a possible human carcinogen.
  • Studies warn against the reuse of PTE containers, as they can leech phthalates after their initial use.
  • Antimony, a toxic metal that can cause damage to the heart muscle, is used in the manufacture of PTE, and concerns remain over whether it leeches into food and beverages.


  • PTE is easily melted down to make fibers, so it's often recycled to make carpets, fiberfill, and fabric for shopping bags.

Read more about upcycling

#2 HDPE: high density polyethylene

High density polyethylene is a thermoplastic that can withstand moderately high temperatures, up to 230ºF, continuously. It is harder and has more tensile strength than low-density polyethylene. Milk jugs, Tyvek mailing envelopes, shampoo bottles, contamination suits and landfill liners are made with HDPE.


  • HDPE is generally considered a low health hazard for items with a short shelf life.
  • Researchers studying water samples bottled in HDPE containers discovered the containers were responsible for elevated levels of barium and zinc. High levels of barium can affect the nervous system and cause cardiac arrhythmia, while excessive zinc can prevent iron and copper absorption.


  • Between energy and raw materials, it takes 1.75 kilograms of crude oil to make 1 kilogram of HDPE.

Read more about chemicals that harm the thyroid

    #3 PVC: polyvinyl chloride (also labeled vinyl)

    PVC is a commonly plastic, with flexibility ranging from rigid to elastic. Bis(2-ethylhexyl) phthalate, or DEHP, is commonly added to PVC to increase elasticity, and some vinyl products contain as much as 40 percent DEHP. PVC is used to make shower curtains, plumbing pipe, vinyl flooring and some cling wrap products.


    • PVC's main building block, vinyl chloride, is classified as a carcinogen by the EPA.
    • DEHP is an endocrine disruptor, and it may effect development and reproductive processes, particularly in male infants. The EPA classifies DEHP as a probable human carcinogen.
    • A study linked PVC flooring and textile wall materials to a doubled risk of bronchial obstruction.
    • A 1999 study out of Sweden linked PVC in the home to asthma symptoms in young children, and a follow-up study examining possible links between environment and autism spectrum disorders indicated PVC flooring, and particularly PVC flooring in the parents' bedroom, may be a factor.


    • Chlorine, a component of PVC, is very harmful to wildlife, causing deformities, reproductive damage and death.
    • PVC is one of the world's largest sources of dioxins, a group of extremely toxic chemicals. Dioxins are released during manufacturing in a byproduct, ethylene dichloride tars, which are generally dumped or incinerated. More dioxins are released when PVC is burned in residential or industrial fires or as a waste control measure.
    • According to Greenpeace, less than 1 percent of PVC is recycled, due to technical difficulties involved in recycling and the associated high cost.

    #4 LDPE: low-density polyethylene

    LDPE is a lightweight plastic and is much more flexible than HDPE. Bread, frozen food and grocery bags, soda rings, plastic wrap, film for baked goods packaging, coatings on milk cartons and squeeze bottles are all LDPE plastics.


    • One of the safer plastics, LDPE is not considered a carcinogen or an endocrine disruptor.


    • These bags can be recycled into new bags or plastic lumber products, but the cost of shipping it to recycling plants is high.
    • Seabeds are littered with plastic bags near coastal regions.
    • Birds and marine life often become entangled in soda rings and eat plastic bags.

    Read more about everyday chemicals that decrease fertility

    #5 PP: polypropylene

    Polypropylene is regarded as one of the most stable plastics; it has a very high melting point and is resistant to repetitive stress. Yogurt and other food containers, some cups and reusable food containers, thermal underwear and rope are all made with polypropylene.


    • Polypropylene is not known to leech any chemicals, and is considered one of the safest plastics for human health.


    Read more about food labeling creating waste and harming the environment

    #6 PS: polystyrene

    Polystyrene comes in expanded form, which is often referred to by the band name Styrofoam, as well as solid form. Polystyrene is used to make a wide variety of products, including CD cases, disposable utensils, take-out food containers, packing materials and meat trays.


    • Studies suggest endocrine disrupting chemicals in polystyrene migrate from PS containers into foods when the containers are headed, in microwaves or otherwise.
    • When burned, polystyrene releases toxic chemicals, including styrene monomer, benzene, other hydrocarbons and carbon monoxide.
    • Research suggests styrene affects the central nervous system in chronically exposed workers.
    • Benzene is a volatile organic compound, and a known carcinogen.
    • According to the U.S. Centers for Disease Control and Prevention, benzene exposure can harm bone marrow and the immune system, and it can cause a decrease in red blood cells that can lead to anemia. It has also been linked to low birth weights in animals.


    • The cost of shipping and recycling expanded polystyrene (foam) is higher than making new PS from oil, so it's rarely recycled and mostly ends up in landfills.
    • When burned, polystyrene releases carbon monoxide and carbon dioxide, which contribute to global warming.

    Read more about sodium benzoate

    #7 Other

    All plastics that don't fit in any of the other categories, or are unknown (usually because they are unlabelled imports) are assigned the number 7. Included in this catch-all category are polycarbonate containers, which contain BPA, and bioplastics made from corn and other plants. Plastic bottle caps, lids, imported containers, polycarbonate baby bottles are just a few of the products that fall under the #7 category.


    • These are miscellaneous plastics, so the health effects vary widely; many health and environmental organizations suggest caution when using products labeled with the number 7.
    • BPA is an essential building block of polycarbonate plastics, and there is growing concern about the potential for this chemical to act as an endocrine disruptor and to impact reproductive health.


    • Number 7 plastics are rarely recycled because they could contain any number of chemicals. Unless a company has their own take-back recycling program (such as Aveda's bottle caps program), you can pretty much guarantee they'll end up in landfills.


    Image: Bo Eide

    By Cara Smusiak| August 23, 2014
    Categories:  Live
    Keywords:  Miscellaneous Green

    About the Author

    Cara Smusiak

    Cara Smusiak

    Cara believes using natural products and eliminating harsh or synthetic chemicals leads to a healthier, happier lifestyle. She grew up in a family that recycled just about everything, avoided harsh cleaners and heavily-scented products, and often turned to holistic medicine. Cara has degrees in art history and journalism, and has taken classes in environmental toxicology and environmental geology. She is passionate about healthy and natural living, environmental awareness and policy, and holistic health care.

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