When it comes to choosing which plastics are the best or most safe, remember this:
Zero is best. 2, 4, 5 if you must.
And of course you must.
Besides homesteading in Maine, off the grid, recreating life from the 1880’s, it is nearly impossible to avoid plastics. But we should try to minimize their use, for our own health and for the greater health of the planet.
The damage already done by plastics will be apparent for millennia, as plastics do not readily degrade. They are microscopically choking our waterways and oceans, and macroscopically filling our landfills and environment. A full accounting is outside the scope of this post, but besides choosing alternatives to plastic in our everyday lives, how can we differentiate among the various types of plastic in terms of potential harm? One way is to consider the recycling number assigned to many plastic containers.
What do the plastic numbers mean?
A classification system was developed in 1988 to differentiate between the various types of plastic in order to facilitate recycling. Plastic manufacturers are not required by law to imprint the classification number on their products, but many do. A convenient outcome of this system is that we can be selective in terms of what we bring into our homes, how we prepare and eat food, etc.
Here are the numbers:
#1 PET or PETE – polyethylene terephthalate. Used in many juice, soda, water, nut butter, salad dressing, and detergent containers. May leach antimony trioxide, which in higher doses causes respiratory and skin irritation, menstrual problems, higher risk of miscarriage, and slower growth of newborns in the first year of life.
#2 HDPE – high-density polyethylene. Used in opaque milk, water, juice, bleach, shampoo, yogurt, margarine, cereal box liners. Considered fairly safe.
#3 PVC – polyvinyl chloride. Used in toys, cling wrap, clear food packaging such as cling-wrapped meats and cheeses, shampoo bottles, cooking oil, nut butter containers, shower curtains, window blinds, pipes and siding. PVC is definitely bad. It leaches phthalates (DEHP or BBzP) which are used as softeners. Phthalates mimic estrogen in the human body and are endocrine system disruptors. They have been linked to asthma, allergies, certain types of cancer, and have negative effects on the liver, kidney, spleen, bone, and body weight. The manufacturing of PVC is also quite toxic to the environment.
#4 LDPE – low-density polyethylene. Used in shopping bags, dry cleaning, bread and frozen food bags, plastic wraps, and squeeze bottles such as for condiments. Considered fairly safe.
#5 PP – Polypropylene. Used in food containers such as yogurt, butter, ketchup, straws, Rubbermaid and opaque plastic containers, baby bottles. Considered fairly safe.
#6 PS – polystyrene. Used in Styrofoam, egg cartons, disposable cups, bowls, take out restaurant containers, plastic cutlery, CD cases. Leaches styrene which mimics estrogen and can disrupt the endocrine system. Can cause reproductive and developmental problems, brain and nervous system effects, and adverse effects on red blood cells, liver, kidneys, and stomach. This is also present in secondhand smoke, off gassing building materials, car exhaust and even drinking water. Benzene, a known human carcinogen, is used in the production of most styrene. This type of plastic is difficult to recycle and so mostly finds its way into the earth’s dumps and oceans.
#7 other. Other types of plastic are lumped together in this less specific category. Some like polycarbonate may be harmful, while others may be safer including newer biodegradable, plant-derived plastics made from corn/potato starch or sugar cane. Avoid polycarbonate, which is found in some plastic baby bottles, sippy cups, sports water bottles, large water storage containers, metal food can liners, and some juice and condiment containers. It leaches BPA, a harmful endocrine disrupter.
Two other plastics under #7 include acrylonitrile styrene AS, and styrene acrylonitrile SAN, which are higher quality plastics with increased strength, rigidity, and temperature and chemical resistance. Another type of #7 plastic is copolyester, which is under the trade name Tritan and the ingredients used to manufacture have not been publicized.
If you have to use plastic, which plastic numbers are considered safer?
#2, #4, #5 (and maybe #7 if not polycarbonate?)
Which plastics are potentially the worst?
#1, #3, #6, #7 polycarbonate
Eat fresh. Seek out glass containers. And remember the code: Zero, 2, 4, 5.
But to undermine the whole system just noted above, at least one study found that almost all plastics #1-7 exposed to common-use stresses release chemicals with estrogenic activity anyway.
Avoiding plastic is nearly impossible if you live in civilization. Hopefully the dose makes the poison, and so doing what you can to reduce plastic in your life seems prudent for your health, and the sad state of our plasticized planet. And when science fails to inspire, read the poetry of Radiohead’s Fake Plastic Trees.