Water bottles sure are convenient, but are they safe?
If you’ve ever turned your water bottle upside-down, you may have noticed letters and numbers near the recycling symbol that indicate what kind of plastic they’re made of.
Unless you know what to look for, these numbers can be more confusing than helpful. Here’s what you need to know.
#1 PET or PETE
This kind of plastic is the most common variety used to make single-use water bottles. Unfortunately, it’s also one of the most toxic plastics.
The plastic leaches carcinogenic chemicals and endocrine disruptors into the liquid it contains, which is made worse by repeated use and exposure to heat. That’s why plastic water bottles shouldn’t be stored in the sun or used to contain juices or other acidic drinks.
This plastic is also hard to decontaminate, making it prone to bacterial or fungal growth. Proper cleaning requires harmful chemicals that may further enhance leeching or directly contaminate water stored in the bottle.
Bottom line: Avoid if you can, recycle after use and keep away from heat.
#2 HDP or HDPE
High-density polyethylene (HDPE) is a plastic commonly used in the production of water and juice bottles as well as grocery bags. It is a very stable and hardy plastic and does not break down when exposed to extreme temperatures. It’s also easy to recycle and does not to leach any chemicals that are suspected of causing cancer or disrupting hormones.
Bottom line: Relatively safe.
#3 PVC or 3V
Polyvinyl Chloride is a flexible plastic used to make anything from plastic food wrapping to children’s toys and plumbing pipes because of its durability. However, this plastic often contains phthalate which can contribute to obesity, insulin resistance, reproductive disorders, and fetal malformation. Some phthalates, like di-2-Ethylhexyl phthalate (DEHP), are suspected human carcinogens.
Infants and children are particularly vulnerable to these chemicals, but even phthalate-free PVC contains other harmful substances like volatile organic compounds (VOCs), lead, cadmium, and other heavy metals as well as dioxin, a carcinogen.
Bottom line: Avoid at all costs and never give to children.
Low-density polyethylene doesn’t typically appear in plastic bottles, but it can appear in squeezable bottles and plastic bags. The substance doesn’t release any chemicals into the water, is much less toxic than other plastic, and is typically considered to be safe for food use.
Bottom line: Safe, but probably not the best bottle to use.
Polypropylene is durable, heat-resistant, and appropriate for reuse. It actually serves as an excellent barrier against moisture, grease, and chemicals. The substance is hazardous during production but studies have determined it to be safe from carcinogens and endocrine disruptors.
Bottom line: Relatively safe.
Polystyrene is inexpensive and lightweight, so it’s used in a large variety of products, including styrofoam and plastic cutlery. The product is known to leech benzene, butadiene, and styrene, which are all known carcinogens. The plastic also leeches other unhealthy chemicals known for reproductive toxicity.
PS plastics are rarely recycled and mostly end in landfills or in the ocean. In fact, it’s not uncommon for fishermen to find the plastic in the bellies of their catch of the day.
Bottom line: Don’t buy and don’t use it. Recycle any existing bottles at home.
#7 PC or non-labeled plastic
This category is a catch-all for polycarbonate and other plastics. Polycarbonate is known to contain BPA, which “has been shown to interfere with reproductive development in animals and has been linked with cardiovascular disease and diabetes in humans. Polycarbonates also contain xenoestrogen, a known endocrine disruptor. This plastic is mainly found in reusable water bottles and baby bottles.
Although BPA-free bottles are on the market, they aren’t much safer. BPS, the compound used to replace BPA can disrupt normal cell functions and contribute to metabolic disorders, birth defects, asthma, or even cancer.
“[Manufacturers] put ‘BPA-free’ on the label, which is true. The thing they neglected to tell you is that what they’ve substituted for BPA has not been tested for the same kinds of problems that BPA has been shown to cause. That’s a little bit sneaky,” says Cheryl Watson, a specialist in cancer research, cell biology, and endocrinology at The University of Texas Medical Branch in Galveston.
The Scientific American also reports that Hong-Sheng Wang, an associate professor at the University of Cincinnati, found that both BPA and BPS cause heart arrhythmia in rats. Needless to say, #7 plastic should be avoided at all costs.
That is unless they are compostable. That’s right, compostable bottles have also ended up in category #7. You can tell them apart from their toxic counterparts because they have initials “PLA” near their recycling symbol. This compostable plastics are much safer than nearly all the products on this list but should not be reused or recycled.
The bottom line: Don’t be fooled by BPA-free products. Compostable bottles are a great alternative but the best option to carry around a reusable glass bottle and fill it up throughout the day.