Have you ever wondered what the number in the triangle on the bottom of your plastic water bottle, beauty, medication, and supplement containers means? Originally, I thought it was only for recycling purposes. I recently discovered that it means a whole lot more. In this blog, we’re talking all about what to look for when it comes to plastics, how you can reduce your plastic exposure, and why small changes can make a difference. Read on to learn more!

Plastics: The Rise and Fall

The world’s first synthetic plastic was invented in New York in 1907 by Leo Baekeland. Due to its low cost, versatility, and ease of manufacture, plastics prevailed over traditional materials like wood, metal, glass, and bone.

Here’s a little fun fact: Leominster, Massachusetts, was once the hair comb capital of the United States with its roots in the hair-care industry dating back to before the Revolutionary War. Combs were originally hand-made from bones, horns, ivory, and even tortoise shell before the advent of celluloid, a flammable and moldable plastic synthesized from the chemical compounds of camphor and nitrocellulose. Essentially, the introduction of celluloid provided a much-needed alternative to ivory and helped reduce harmful animal poaching.

During World War II, plastic, which had now become more capable through advancements in chemistry and engineering, was being monopolized by the military to conserve more valuable commodities like rubber. The U.S. Army even went so for as to order all servicemen to receive the standard issue black five-inch plastic comb that still exists to this day.

Consumer demand in the Postwar Economy put plastic production on the fast track. Interest in plastic piqued at this time because it could be shaped and molded into absolutely anything, and it could even be dropped without shattering like glass.

Environmental concerns over plastic began to rise in the 1970’s and 1980’s because, though disposable, it was not biodegradable. The realization that plastic lasts forever was the primary concern among many, including environmental activists. As a response, the plastic industry, in part, started the movement toward recycling. However, recycling has never been a perfect solution because most plastics still end up in our landfills, and even in our oceans. As plastics degrade, the particles are ingested by living creatures in the ocean. We, and even our pets, may now be consuming contaminated fish.

Studies have shown that the chemical compounds in modern plastics contribute to many health-related problems, such as early puberty in females, reduced sperm count, infertility, obesity, and even increased rates of some breast, ovarian, testicular and prostate cancers. Additionally, the chemicals in plastic has been documented through multiple studies to mimic the actions of naturally occurring estrogens. This is known as an estrogen disruptor.

The good news is that researchers are working on formulas to make plastic from plant-based ingredients rather than petroleum and other chemical compounds. In the meantime, a conversation needs to be had to address the health risks associated with our current plastics.

Let’s start with those numbers inside the recycling triangle to see what they actually mean.

#1 – PETE or PET (Polyethylene Terephthalate)

It’s found mostly in soda bottles, water bottles, beer bottles, salad dressing, medication, supplement, peanut butter, beauty product containers, and mouthwash bottles. This plastic is known to allow bacteria to accumulate. Plastic #1 is recycled into tote bags, furniture, carpet, paneling, fiber, and polar fleece.

 #2 – HDPE (High Density Polyethylene)

It’s typically opaque and found mostly in milk jugs, household cleaner containers, juice bottles, shampoo bottles, cereal box liners, detergent bottles, motor oil bottles, yogurt tubs, butter tubs, detergent bottles, juice bottles, and toiletry bottles. This plastic is considered safe and has low risk of leaching. Plastic #2 is recycled into pens, recycling containers, picnic tables, plastic lumber, benches, fencing, and detergent bottles.

#3 – V or PVC (Vinyl)

It’s found in shampoo bottles, clear food packaging, cooking oil bottles, medical equipment, piping, and windows. Prolonged exposure to this series of plastic has been linked to cancer. Plastic #3 is recycled into paneling, flooring, speed bumps, decks, and roadway gutters.

#4 – LDPE (Low Density Polyethylene)

It’s considered to be safe and mostly found in squeezable bottles, shopping bags, clothing, carpet, frozen food, bread bags, and some food wraps. Plastic #4 is recycled into compost bins, paneling, trash can liners and cans, floor tiles, and shipping envelopes.

#5 – PP (Polypropylene)

It’s also considered relatively safe and is typically found in straws, utensils, cups, yogurt containers, ketchup bottles, syrup bottles, and medicine bottles. Plastic #5 is recycled into brooms, auto battery cases, bins, pallets, signal lights, ice scrapers, and bicycle racks.

#6 – PS (Polystyrene)

It’s mostly found in compact disc cases, egg cartons, meat trays, and disposable plates and cups. Plastic #6 is recycled into egg cartons, vents, foam packing, and insulation.

Plastic #7 – Other, Miscellaneous

It’s mostly found in sunglasses, iPod cases, computer cases, nylon, 5-gallon water jugs, and bullet-proof materials. Plastic #7 is recycled into plastic lumber and other custom-made products.

These plastics pose the greatest risks due to possibly containing hormone disruptors like BPA, which has been linked to infertility, hyperactivity, reproductive problems, and other health issues.

What’s the bottom line?

You can’t avoid all plastics, but when possible look for products with the numbers 2, 4, and 5 inside of the recycling triangle, since these plastics are regarded as the safest. Making small changes can be beneficial to your health and that’s what it’s all about!

Here’s some simple swap ideas to reduce plastic exposure:

For other health and wellness content, check out these blogs:

How to Develop Healthier Habits
7 Ways Your Physical Health is Connected to Your Mental Health
10 Ways to Stay Healthy When Working from Home


Joseph L. Nicholson and George R. Leighton, “Plastics Come of Age,” Harper’s Magazine, August 1942, p. 306.
Susan Freinkel, Plastics: A Toxic Love Story (New York: Henry Holt, 2011), p. 4
National Research Council 1999

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