WASHINGTON — A long-awaited study from former U.S. Surgeon General C. Everett Koop has found that phthalates are completely safe in vinyl medical devices and toys.
The study, released June 22, was designed as an independent review by the well-known Koop and was received warmly by the industry. PVC manufacturers said the report will assuage public concerns that had prompted some toy makers and health-care companies to look for alternatives to vinyl.
Koop's report said that even people with long-term exposure to some of the phthalates do not receive doses anywhere
close to the levels that caused problems in lab animals.
His conclusions contrast sharply with a report issued earlier this month by Health Care Without Harm, which said people with long-term exposure can receive troublesome levels of the softening agents.
Falls Church, Va.-based HCWH questioned whether Koop's panel fully reviewed studies on dialysis or blood transfusion patients.
The Koop report looked at di(2-ethylhexyl) phthalate (DEHP), which is used in medical devices such as intravenous bags and tubing, and diisononyl phthalate (DINP), used in toys. Koop chaired the study panel, organized by the New York-based American Council on Science and Health.
``Consumers can be confident vinyl toys and medical devices are safe,'' Koop said. ``There is no scientific evidence they are harmful to children or adults.''
Removing DEHP would pose risks for patients because DEHP can improve medical devices, double storage time for blood bags and improve transparency and resistance to kinking, the report said. There are no good replacements in the United States for some applications, like tubing in flow-control devices, the report said.
HCWH said there are safe alternatives for some applications, such as non-PVC IV bags, which have been used for 12 years, and tubing without DEHP.
Much of the research on animals is not relevant to people because humans process the two phthalates differently, said Koop, who was interviewed along with four other members of the ACSH review panel in Washington.
Lab animals in tests typically ingest the phthalate, while human exposure from medical devices is intravenous. Ingestion exposure is more dangerous because it is metabolized much faster, said Ronald Brecher, a panel member and principal at GlobalTox International Consultants Inc. in Ontario.
``That difference in metabolism really is crucial and is part of what led us to the conclusion that DEHP in medical devices is not harmful to patients,'' he said.
Dr. Ted Schettler, an HCWH spokesman, said some animal studies have been done intravenously, and relevant animal studies do raise concerns. If Koop's panel only asked about direct evidence of harm to people, it would find little because there are not many human studies, he said.
The Koop report said more research is needed on how much DINP children are exposed to when they suck on vinyl toys. But the panel felt that the evidence available on children's exposure does not suggest problems.
``The problem that was presented to the public was, `Throw away all of your plastic teething rings and toys because your kids are eating toxic stuff,'*'' Koop said.
But he said the animal studies are based on animals being given daily doses throughout their lives, exposing them to 150 times what people could receive, while children suck on the toys for only a few months.
``Taken in conjunction with everything else ... the weight of evidence does not in any way hint that we are in trouble,'' Koop said.
Koop also was critical of a Consumer Product Safety Commission decision in December, which urged manufacturers not to use DINP but said it could find no evidence that children were being harmed.
``I don't think you frighten the public until you have some evidence to go on, and to take some single animal experiment that doesn't have much to do with ... homo sapiens is irresponsible,'' Koop said.
Panel member Kimberly Thompson, a professor of risk analysis at Harvard University's School of Public Health, said: ``This is not a public health problem we should be spending a lot of resources on. There are many other problems related to children or medical questions that deserve more attention.''
The Koop report's objectivity was criticized by the National Environmental Trust, which said that the ACSH received 76 percent of its funding from corporations, including some of the United States' largest manufacturers of phthalates. Washington-based NET said chemical manufacturers were over-represented on the panel.
ACSH spokesman Jeff Stier said the panel was made up of independent scientists who reached conclusions based on ``where the science takes us.'' ACSH frequently has taken positions critical of groups that fund it, such as Kellogg Co. and Coca-Cola Co., he said.
``They are really alleging that Dr. Koop was bought out by industry,'' he said. ``That doesn't pass the laugh test.''
Stier said ACSH gets less than 50 percent of its funding from corporations. Some of the largest makers of phthalates in the United States contribute to ACSH, he said.
Vinyl industry officials questioned the objectivity of the HCWH report, noting that its author, Joel Tickner, was active in Greenpeace's anti-PVC campaign. A HCWH spokeswoman said Tickner was hired because he has done research on phthalates: ``We don't feel he produced any biased spin.''