For those of us interested in nontoxic personal care, trying to navigate the ever-growing list of chemicals to avoid can be overwhelming. Phthalates are on the Environmental Working Group’s “Dirty Dozen List Endocrine Disruptors,” but what exactly are they and what harm do they cause?
Phthalates are a group of chemicals used to make certain plastics softer, more flexible, and less fragile. Two million metric tons of them are produced each year!
Sound like a lot? It is… That’s 4,409,245,244 lbs, which equals the weight of 367,437 African elephants or 6 Empire State Buildings! Each. Year.
There are over 20 different types of phthalates that are commonly used in hundreds of products, such as:
Exposure to phthalates can occur by ingestion, inhalation, and through skin contact. Plastic storage containers can contaminate foods and drinks. We can breathe dust that has come into contact with vinyl wallpaper, mini-blinds, shower curtains, or recently installed vinyl flooring. When we put phthalate-containing cosmetics on our skin and near mucous membranes we can absorb small amounts.
Of particular concern are the phthalates used in medical equipment. It can pose a problem for those who often need IV medical treatments, such as dialysis patients or hemophiliacs who require blood transfusions.
Phthalates and their effects can be an occupational hazard for those who work in plastic manufacturing or with the many industrial products which contain chemicals. Those at risk include individuals who work in home construction and remodeling, painters, printers, and those who work in plastics manufacturing.
At the greatest risk for exposure however are children, especially in-utero during the crucial stages of fetal development. Babies and toddlers under 36 months of age are also at risk because they naturally put things in their mouth, especially their toys (which are often plastic).
The greatest concern is the way phthalates affect reproductive organs and hormones, especially in prepubescent males. Some have been linked to breast and other cancers, allergies, obesity, thyroid, and other hormonal disruption.
To understand these risks in greater detail, let’s look at three specific phthalates.
DEHP or DOP is most commonly used as a plasticizer in polymer products, often in flexible PVC. Flexible PVC (polyvinyl chloride) is used to make a number of products including building materials such as roofing, cables, flooring, and plumbing pipes. DEHP is also used to make blood bags and dialysis equipment.
DEHP is in consumer products such as shower curtains, car interiors, and even exercise balls. The highest exposure from consumer products occurs in children and comes from toys and other products related to childcare. Infants can be exposed to 6 mg/kg/day of DEHP through breastmilk, or 13mg/kg/day through formula.
It is also possible to be exposed to DEHP, and other phthalates through the environment, especially for those who live near industries that use the chemical. Even those who don’t live near manufacturing facilities can be exposed through water runoff from landfills, PVC pipes, and from buildings constructed with DEHP. This is one reason we make it a priority to use air and water filters at home.
Studies investigating the toxicity of DEHP have shown it affects two organs in particular: the testicles and kidneys. It can increase the size of kidneys, and the occurrence of kidney stones as well as the size of the stones.
DEHP can also cause atrophy of the testes, decreasing their size and under very high dosages causing changes to sperm. It seems that pre-pubescent males are more sensitive to their effects than adults.
Studies also show that DEHP can interfere with the function of the male endocrine system, affect sexual development, and lower fertility in mice and rats.
Based on these studies, the European Union established the amounts of DEHP needed to produce toxicity and negative effects as being equal or greater than the following:
For comparison, the highest DEHP exposures come from necessary and lifesaving medical equipment and procedures. Adults receiving long-term hemodialysis will produce DEHP metabolites in the urine at levels of 3.1 mg/kg/day and neonatal blood transfusions can generate metabolite levels of 1.7mg/kg/day in infants.
According to a survey conducted by the FDA in 2010, DEP is the only phthalate still commonly used in cosmetics as solvent and fixative in fragrance. In 2001 the fragrance industry was using around 4,000 tons of DEP annually.
Because of laws in place to protect fragrance formulations, companies do not have to disclose the ingredients of the fragrances put into products such as perfumes, make-up, hair care products, laundry detergents, fabric softeners, or even candles.
Other cosmetic products which often include DEP are bath oils and salts, eye shadow, hair spray, aftershave lotions, nail polish, and nail polish remover.
It can also be found in toothbrushes, plastic packaging, mosquito repellant, and even as an ingredient in aspirin coatings.
The European Union recommends the daily permitted exposure level of DEP to be 4mg/kg/day. This is a much higher level than others because it is considered to be one of the safer phthalates. In animal studies, it took much higher doses than this to produce negative effects.
Often, side effects were only observed in the offspring of the rats given doses of DEP, suggesting that the effects may be longer term than what has currently been studied. These developmental defects were delayed ear unfolding, delayed eye opening, and delayed vaginal opening in first generation pups.
Embryo-fetal development studies carried out on mice and rats also observed a reduced number of pups per litter, reduced pup weight at birth, and an increased frequency of skeletal “variations” in pups after pregnant females were given high doses of DEP. Males also had decreased epididymal sperm concentrations.
A 2003 report from the World Health Organization on the chemical stressed that these studies may not prove conclusive. DEP is present in the majority of laboratory equipment, therefore it is difficult to prevent contamination in control groups.
We can be exposed to DEP through food that has been stored or shipped in plastic packaging. One study from Great Britain found that baked goods placed in boxes made from thin cardboard with plastic windows containing DEP had concentrations of the phthalate of 1.7-4.5 mg/kg even though the food had not touched the plastic!
Low levels have even been detected in aluminum foil packaging. Like other phthalates, we can also be exposed to DEP via our water, air, and medical equipment.
Thankfully, surveys conducted in the early 2000s found that the average exposure levels of DEP were way below 4 mg/kg/day. One example is an American survey from 2000 which tested 97 women aged 20 – 40 years and found that the median exposure was 13mg/kg/day, (13 micrograms/kilogram of body weight/day) and the maximum concentration was 170mg/kg/day, which is 23.5 times less than the recommended daily limit of 4mg/kg/day.
Currently, DEP is considered to pose no health threat to humans and is therefore not regulated.
DBP is has a lower molecular weight than other phthalates and is often used in combination with those of higher weights, especially DEHP. It is used as a solvent in many oil-soluble dyes, in printing inks, sealants and grouting agents, adhesives, film coatings, insecticides, other organic compounds, as well as a fiber lubricant in textile manufacturing. It has also been used as a perfume solvent and fixative, a suspension agent for solids in aerosols, a lubricant for aerosol valves, and a plasticizer in nail polish.
A major concern regarding DBP to consumers is its toxicity to reproductive organs and hormone pathways. According to a report published by the Committee for Medicinal Products for Human Use, a subset of the European Medicines Agency, DBP is believed to disrupt the “development of androgen-dependent structures in animals by inhibiting fetal testicular testosterone biosyntheses.”
The European Union has banned the use of this ingredient in toys, childcare articles, and cosmetics. The State of California has classified it as a reproductive and developmental toxicant. Studies have demonstrated that DBP can change the expression of genes important in the synthesis of sex hormones and in the development of the reproductive organs.
DBP has also been correlated with changes in sperm motility and decreased sperm concentration, decreased fertility, and changes in hormone levels in adult men, according to the EWG.
This being said, there is not enough evidence to conclude that is carcinogenic, though some sources suggest that the mounting evidence points to this.