What do your raincoat, hairspray, food storage containers and garden hose all have in common? Each item likely contains phthalates (pronounced THAL-eights), a group of chemicals known as plasticizers that make plastics more flexible and harder to break.
While these ubiquitous chemicals help create many of our everyday items, they also come with health risks that are increasingly worrying to scientists and researchers.
What Are Phthalates?
As mentioned, phthalates are chemicals used to make plastics stronger. They're often known as plasticizers and used a lot in polyvinyl chloride (PVC) plastics. These are found in all sorts of consumer products we use all the time, from food packaging and cosmetics to medical supplies and even children's toys.
There have been only a few studies that examine the health effects of phthalates on humans, and to date, most of that research looks at the effect of a single phthalate, not the chemical mixture, according to Stephanie Eick, an environmental epidemiologist at the University of California San Francisco.
In addition, Eick says, it is difficult to find a group of people who aren't exposed to phthalates at some level, making it hard to do an experiment with a control group. And since humans are exposed to multiple chemicals at a time — not just phthalates — it's also difficult to parse out the effects of specific phthalates.
How Are We Exposed to Phthalates?
Humans are exposed to these chemicals in a few ways. The first is by consuming them through food. Food can get exposed to phthalates during production through the plastic tubing used for liquids; via contact with food preparation gloves; and through plastic storage containers. In particular, foods that are high in fat absorb more phthalates during processing.
Infants are also likely to be exposed by because they often put plastic objects containing these chemicals directly in their mouths. And people who work in industries where products with higher concentrations of phthalates are used are also at higher risk of exposure, for example people who work at hair and nail salons, as many beauty products are known to contain phthalates.
Do Phthalates Pose Health Risks?
Experiments on lab animals have found that exposure to phthalates is associated with reproductive health and developmental problems, such as early puberty and interfering with the hormone system. This is because phthalates are weak endocrine disruptors and block androgen, a group of hormones that regulate masculine traits and reproductive activity. This means that when absorbed in the body, phthalates can suppress the hormones involved in masculine sexual development or mimic or block the hormones involved in feminine trait development.
Based on the results of some human studies, exposure to phthalates can lead to impaired brain development in children, making exposure among children and pregnant woman the most dangerous.
"Studies have shown that children born to mothers who were exposed to high levels of phthalates were more likely to develop ADHD, behavior problems, and have a lower IQ compared to children born to mothers who were exposed to lower levels of phthalates during pregnancy," Eick says. Other studies also suggest that exposure can lead pregnant people to give birth prematurely.
Lower income and underserved populations are also at higher risk. "If someone is lower income, this could lead them to experience food insecurity," Eick explains. "Foods that are generally cheaper often contain higher levels of chemicals, such as phthalates, and thus some underserved populations often experience food insecurity and have higher levels of chemicals, which can have a joint impact on health."
How Can We Avoid Exposure?
The easiest way to limit exposure to phthalates is to reduce your use of plastic. Of course, this is easier said than done, as nearly everything comes in plastic nowadays. However, when it comes to consumer products, one step you can take is to read labels, as phthalates are required to be listed in the ingredients.
There are also beauty companies that now indicate on their shampoos or lotions packaging that they are phthalate free. In addition, Eick recommends checking the Environmental Working Group's Skin Deep webpage, which has a comprehensive list of consumer products and their ingredients.
In terms of what people can do to avoid exposure through food, Eick has a few suggestions. "With respect to storing leftovers and other foods, it's best to use glass containers when possible," Eick says. "If it's not possible to avoid using plastic containers, it's best to let the food cool down to room temperature before putting the food in the plastic container and to not microwave food in plastic."
Given how ubiquitous phthalates are, it would likely be difficult to ban them outright. However, scientists published an editorial in the April 2021 edition of American Journal of Public Health, which included a call for better federal regulation of these chemicals. From the authors:
While Eick was not part of that editorial, she said she agrees that it would be a good idea to regulate phthalates as a class, as opposed to regulating specific phthalates. However, she also notes that bringing in phthalate replacements, which might seem like a nice fix, could quickly backfire.
"This happened with BPA, where BPA was phased out and BPA replacements were phased in," Eick says, "and now we're starting to see that these BPA replacements are also harmful."