Alexandria, Virginia - Chemical additives found in a range of consumer products from baby bottles to toys to intravenous drip bags may well be dangerous to humans, a panel of experts said on Thursday, but they said they needed more time to decide.
Members of a panel asked to determine the health risks from the chemicals, known as phthalates, had been expected to issue a final report on their findings on Thursday, but ran out of time before reaching consensus.
While they said there was little disagreement over what the studies show - that the chemicals can disrupt reproductive functions such as fertility in laboratory animals - what was not clear was whether they affect humans.
"Some of the phthalates we looked at, like DEHP and BBP, are reproductively toxic in rats and mice," Robert Kavlock of the Environmental Protection Agency (EPA), who chaired the panel, told reporters.
"When exposure happens earlier in life, the effects tend to be more severe."
Dr Lynn Goldman, a pediatrician at Johns Hopkins University in Baltimore and senior scientific adviser to the National Toxicology Programme (NTP), agreed. "You can see both developmental impacts ... like birth defects, and reproductive effects on sperm and fertility," she said.
But she added, "Even though there is a lot of production of these chemicals and even though there is a lot in the environment, we know very little about what human exposure is."
Goldman said the chemicals, used to soften plastics, can leach out. "Some are used in fairly sensitive areas such as blood tubing and IV bags where, if they are coming off, they have the potential to go directly into a person."
In June a coalition of 181 health, religious, labour and environmental groups, called Health Care Without Harm, petitioned the Food and Drug Administration (FDA) to warn patients about phthalates in IV bags.
The environmental group Greenpeace said phthalates could leach from soft vinyl toys into the mouths of children when chewed or sucked, and in December the US Consumer Product Safety Commission asked the nation's toymakers to remove phthalates from baby rattles and teething toys.
But the chemical industry and groups such as the Health Industry Manufacturers Association say products using phthalates are safe. An earlier panel chaired by former US Surgeon General Dr C. Everett Koop agreed.
The new panel - the first of its kind to examine a chemical in such a way - was asked to determine whether the population is at risk from the chemicals.
Goldman would not say which way the group was leaning.
The panel, appointed by the Centre for the Evaluation of Risks to Human Reproduction, itself a branch of the NTP and the National Institute of Environmental Health Sciences (NIEHS), will try to meet again later this year.
"The decision was to have more discussions, so that we feel comfortable (with any statement)," Goldman said.
The committee, appointed earlier this year, includes experts in toxicology, pediatricians and others. They heard evidence from the chemicals and plastics industries, medical experts and advocacy groups, and read more than 1 000 scientific papers looking at the effects of phthalates. - Reuters