A new federal law banning phthalates in children's toys and other kids' products has come into force in the US. But critics are skeptical of the efficacy of the law as companies currently aren't required to publicly disclose the chemicals they use in place of phthalates — and little is known about the health effects of one of the most widely used alternatives.
Phthalates have long been used to make plastic soft and flexible. But the chemicals can leach out of plastic products and enter our bodies, where some scientists suspect they act like hormones. Phthalates have been shown to affect the development of the male reproductive system in lab animals, and a few small studies suggest they may be linked to subtle effects in the reproductive organs of infant boys.
In preparation for the federal ban, manufacturers have been reformulating baby rattles and plastic toys with phthalate substitutes. But the ban doesn't spell out what chemicals they can use to replace phthalates, Sarah Varney reported for
NPR, a well-known alternative radio channel.
California enacted a similar ban on phthalates on Jan. 1. That law does require manufacturers to use substitutes that aren't known to cause cancer or reproductive harm — but it doesn't bar substitutes that might have other adverse health effects.
"There are 80,000 chemicals in commerce," says California Environmental Protection Agency toxicologist Stephen Dizio. "We know something about toxicity of about 400 of them. That really means that things come and go in the marketplace that you have no idea what will happen."
Under federal law, companies don't have to publicly reveal the chemicals in their products or alert any government agency when they swap out a banned chemical, such as phthalates, for a new one.
In California, the two new state laws will eventually require companies to post the chemicals in their products in an online database available to the public. And they will likely have to prove that those chemicals are safe before they're allowed to sell them in the marketplace.
In the case of the U.S. Environmental Protection Agency, it does not routinely assess the risks of new or old chemicals, but it does keep a shortlist of chemicals deemed in need of evaluation.
So far, no phthalate substitute has been added to that list, according to an EPA spokesperson.
Even if one were to be added, evaluations can take years and have rarely resulted in bans.
NPR contacted several dozen toy companies about their use of phthalate substitutes, but most would not comment on which ones they were using, or said their product ingredients are confidential.
Two companies, Learning Curve and Mattel, maker of Barbie, Fisher Price, American Girl and Tyco products, did say they were using citrate-based plasticizers as well as a new chemical called DINCH.
Citrates, or citric acid esters, have been widely tested, and in 2005, European regulators deemed them safe for use in products for children. The additives also are approved in the U.S. and Europe for use in products that come in contact with food, such as plastic wrap and containers.
The German chemical giant BASF started selling the plasticizer DINCH in 2002, and a company official says it is the most widely used phthalate substitute in the world.
However, there are no peer-reviewed, publicly available data on the toxicity of DINCH, and what is widely known comes from animal studies conducted by the manufacturer and given to European food regulators. In those studies, BASF tested the chemical on rats and rabbits, and the results suggested that DINCH does seem to pose some risks to kidney health in animals.
Nearly all chemicals are toxic if given at high enough doses, so scientists usually look for signs of toxicity at low or middle doses. The male rats in the BASF studies developed kidney damage from middle doses. That led European regulators to set a limit on how much DINCH humans should be exposed to each day.
But it's difficult to know how much DINCH children might be exposed to from toys and other products.
While BASF's studies suggest how much DINCH migrates into food from plastic wrap and food containers, there's no good guesstimate for how much DINCH a baby could ingest from, say, a teething ring.
Several toxicologists said that DINCH looks to be a better choice than phthalates for children's products.
It will likely take years of research to assess the safety of DINCH, partly because the methods scientists use to evaluate health risks posed by potentially toxic chemicals are in some cases half a century old.