What Is BPA? Definition and Environmental Impact

BPA stands for bisphenol A, an industrial chemical commonly found in hard plastics and epoxy resins. A host of studies have shown that BPA can harm the reproductive and general well-being of some small mammals and other vertebrate animals. Its effect on human health remains unclear.

First synthesized in 1891, BPA has been used in products that are increasingly ubiquitous in homes since 1957. A 2003 and 2004 survey by the United States Centers for Disease Control and Prevention (CDC) found detectable levels of BPA in the urine of 93% of more than 2,500 Americans six years and older. In 2021, a systematic analysis of data from 15 such studies identified BPA in more than 90% of the urine and blood samples given by a total of almost 29,000 participants.

Despite consumer concern, government regulatory agencies in the United States have not banned BPA. 

Where Is BPA Found?

BPA is in water bottles and food packaging and storage containers. It is also in the epoxy resin that is part of the protective internal coating of many food cans, and it’s found in water supply lines and bottle tops, as well. Eyeglass frames, toys, plastic eating utensils, electronics equipment, helmets and other sports protective equipment, resin-based dental sealants, compact discs, and some medical devices contain BPA. Because it coats thermal papers, BPA can also be found in receipts from ATMs and cash registers.

United States government organizations and the World Health Organization (WHO) have been slow to update their public information about BPA in the environment and the health threats it may represent. The United States Food and Drug Administration (FDA), for one, has noted on its website that its information about BPA is based on studies conducted between 2009 and 2013. 

In 2015, the peer-reviewed journal Dose-Response published an independent, global assessment of where and in what quantities BPA is found. According to that document, the chemical enters ecosystems as part of discharge from wastewater treatment plants and as a result of trash burning, leaching from landfills, and deterioration of plastics that never make it into landfills.

As noted by the National Institute of Environmental Health Science (NIEHS), air, dust, and drinking water can all transport BPA. In soil, low levels of BPA can actually enhance photosynthesis in plants. At higher levels, it decreases photosynthesis.

Recognizing the extent of the public’s concern about BPA, the NIEHS has issued guidelines about which food-related plastic products to use and how to use them safely. NIEHS has also advised consumers to take special care with products that may expose infants and children to BPA.

How to Avoid BPA in Food Containers

The National Institute of Environmental Health Sciences provides the following recommendations to minimize your exposure to BPA in food containers:

• High temperatures accelerate BPA’s migration from plastics into food and liquid. Don’t microwave food or beverages in plastic containers. Use glass or porcelain containers and plates instead.
• If you are going to use a plastic container or bottle, look for a prominent number on the bottom of the item. Those numbers are recycling codes. Containers showing a "3" or a "7" were probably made with BPA. 
• Canned foods are a primary vector through which BPA enters human bodies. Try to reduce your consumption of canned foods. If you must use them, rinse them first.
• Store your food in glass, porcelain, or steel containers. Take special care to do this if the food you are storing is still hot. 
• Make sure that all baby bottles are BPA-free.

Is BPA Dangerous to Animals and Humans?

Despite decade-old assurances by WHO and the Food and Agriculture Organization of the United Nations (FAO) that the amount of BPA typically found in human blood and urine is at a concentration far too low to create illness or reproductive problems, a 2013 review article cited several studies showing an increase in BPA levels in dialysis patients. (These results don’t necessarily demonstrate that BPA causes kidney failure, though they might suggest that BPA makes it difficult for people with impaired kidney function to clear BPA from bodily fluids.) 

Meanwhile, studies with aquatic animals, voles, and mice have created a suspicion that BPA represents a danger to vertebrate animals in general. BPA is an “endocrine disruptor.” This means that it disturbs the way that hormones regulate reproductive health.

As outlined in an article entitled "The Politics of Plastics" that was published in the peer-reviewed American Journal of Public Health, scientists have reported BPA-related distortions in females’ reproductive organs and function and have suggested that the alterations may be due to the fact that BPA closely mimics estrogen, a female sex hormone. BPA also mimics androgen, a male sex hormone. Not surprisingly, studies have shown that BPA threatens the reproductive potential of male seahorses and mice. 

The experiments demonstrating estrogen mimicking have caused exceptional concern, as BPA is structurally very similar to an infamous estrogen mimic, DES (diethylstilbestrol). During the years 1940-1971, DES was widely prescribed to pregnant women in the hopes of preventing miscarriage and premature labor. Unfortunately, as years progressed, women exposed to DES while in their mother’s womb developed multiple health problems, including infertility and malformed reproductive organs. 

BPA in the Environment

BPA breaks down readily in soil and air but not in water. A study by scientists in Turkey that was published in 2019 in the peer-reviewed Bulletin of Environmental Contamination and Toxicology showed that BPA did not begin to degrade in natural river water until after 50 days. In seawater, there were no detectable signs of degradation until after 150 days. 

Easily as important as half-life as a measure of environmental threat from BPA is the volume of the chemical that is poured into the environment each year. Unfortunately, that number is hard to come by. WHO and FAO’s data are from 2009. The most recent EPA estimate of BPA pollution in the environment is an Action Plan dated 2010. In it, the EPA estimated, “Releases of BPA to the environment exceed one million pounds per year.” 

That may or may not be the case for BPA in the United States. Even so, figures collected since 2010 have suggested an astronomically larger figure as well as a rising potential for contamination globally.

For example, in 2016, the U.S.-based market research firm Industry Experts pegged the global consumption of BPA during 2015 at 7.2 million tons. The same company projected that, by 2022, the global annual consumption would be 10.6 million tons.

In 2020, the U. S.-based market research firm ChemAnalyst predicted that global demand for BPA products will rise through 2030 at an average annual growth rate of 4.7%. 

Looking at industry projections is not a reliable way to estimate actual environmental contamination, but in the absence of clearly reported government figures, it may have to do.

Whatever the modern rate of annual BPA production ultimately proves to be, the constancy with which the chemical is incorporated into plastics has prodded some scientists to refer to BPA as "pseudo-persistent" and a "global ingredient of the environment." It’s always there, and this is despite the ease with which it degrades in soil and air.

How Concerned Should We Be for the Environment?

Adequate risk data about BPA seem still to be lacking, which suggests that complacency about its environmental effects is not yet a good idea.  

As plastic production continues to infuse BPA into ecosystems, and as government agencies remain reluctant to take a fresh look at data, the best bet for environmentally concerned scientists may be to find ways to accelerate the biodegradation of BPA.

By definition, biodegradation relies on the presence of microorganisms. Ongoing experiments are testing specific strains and groups of bacteria for ways to transform environmental BPA into less harmful chemical substances.

Other research is looking at microplastics as a potential "sink" (or "sponge") for BPA. The dark side of microplastics, unfortunately, is that they can contain BPA, in which case they would be as likely to be a source as a sink. 

Even while the FDA has elected not to ban BPA, it has advised consumers to reduce their exposure as much as possible. The European Union and a large handful of states in the United States have placed some restrictions on the chemical’s use in toys and water bottles, in food storage containers, and in other plastics meant to contain food and drink.