Vehicle interiors have dangerous levels of toxic chemicals, mainly from flame retardants and plastic softeners, an environmental group warns.

The study, released by The Ecology Center, a Detroit organization, revealed new information about toxic chemical exposure in automobile interiors. PBDEs, chemicals used as fire retardants, and phthalates, used primarily to soften PVC plastics (and partly responsible for "new car smell"), were found in dangerous amounts in dust and windshield film samples.

"We can no longer rely just on seatbelts and airbags to keep us safe in cars," said Jeff Gearhart, the Ecology Center's Clean Car Campaign Director. "Our research shows that autos are chemical reactors, releasing toxins before we even turn on the ignition. There are safer alternatives to these chemicals, and innovative companies that develop them first will likely be rewarded by consumers."

Drivers and passengers are exposed through inhalation and contact with dust. These groups of chemicals have been linked to birth defects, impaired learning, liver toxicity, premature births and early puberty in laboratory animals, among other serious health problems, the group said.

"Most people think about cars causing outdoor air pollution, such as smog," said Gearhart. "Now we know that breathing the air and dust inside of cars may be even more dangerous."

Fortunately, car owners can take some direct actions to minimize health risks from PBDEs and phthalates in car interiors, Gearhart said. They can use solar reflectors, ventilate car interiors, and park in the shade whenever possible.

The study - "Toxic at Any Speed: Chemicals in Cars & the Need for Safe Alternatives" - found that chemicals used to make seat cushions, armrests, floor coverings, wire insulation and other interior auto components are more rapidly released into the air in extreme temperatures.

Since automobiles have 360-degree windows surrounding the interior, cars can heat up to 190 degrees F. In addition, UV exposure from parking in the sun creates a favorable environment for chemical breakdown, causing PBDE flame retardants to become even more dangerous. Solar exposure in cars can be 5 times higher than in homes or offices, according to the study.

The Ecology Center collected windshield film and dust samples from 2000 to 2005 model cars made by 11 leading auto manufacturers. Volvo was found to have the lowest levels of phthalates and the second lowest levels of PBDEs, making it the industry leader in terms of indoor air quality. Volvo also has the toughest policies for phasing out these chemicals.

Other manufacturers claim they have eliminated PBDEs and phthalates from particular applications. For example, Ford reports that it has eliminated PBDEs from "interior components that customers may come into contact with." Honda also reports that it has eliminated most of its phthalate-containing PVC in its vehicles. Other manufacturers tested include BMW, Chrysler, GM, Hyundai, Mercedes, Subaru, Toyota and Volkswagen.

But automakers believe that the chemicals, such as the flame retardants, are needed to protect people in crashes. They have been shown not to pose a risk to occupants, said Eron Shosteck, spokesman for the Alliance of Automobile Manufacturers. The alliance represents the Big 3 and six import-brand companies.

The study found that concentrations of PBDEs in dust and windshield film samples were up to five times higher than those found in homes and offices in previous studies. Since the average American spends more than 1.5 hours in their car every day breathing in these chemicals, the inside of a car is a significant source of indoor air pollution. According to the EPA, indoor air pollution is currently one of the top five environmental risks to public health.

In Europe and Japan, momentum is beginning to move away from toxic chemicals such as PBDEs and phthalates toward safer alternatives. The European Union, for example, passed legislation in 2003 requiring the phase-out of PBDEs in electronic and electrical equipment. As a result, electronics manufacturers such as Apple, Dell, Hewlett-Packard, IBM, Panasonic and Sony have already eliminated PBDEs from their products.

The European Union has also required phase-outs of phthalates in toys, childcare items, and cosmetics, resulting in similar elimination efforts in those industries.