23 Jun 11 Formaldehyde and styrene now considered carcinogenic
Formaldehyde, a chemical widely used in industrial processes, styrene and a family of substances found in some herbal remedies, have been added to the US government’s official list of known human carcinogens, officials have announced.
Six other substances, including styrene, which is used to make coffee cups and food containers, among other products, are now considered to be “reasonably anticipated” to be a human carcinogen, according to the Report on Carcinogens, which was released by the National Toxicology Program.
“Reducing exposure to cancer-causing agents is something we all want,” said Linda Birnbaum, director of the National Institute of Environmental Health Sciences and the National Toxicology Program, in a statement announcing the new listings.
The report is a congressionally mandated list that is prepared for the secretary of the Health and Human Services Department. With the new additions in the 12th version of the report, 240 substances are now listed.
“This report underscores the critical connection between our nation’s health and what’s in our environment,” said John Bucher, associate director of the National Toxicology Report, in a the statement.
A listing in the report does not necessarily mean a substance will cause cancer, according to the announcement. “Many factors, including the amount and duration of exposures, and an individual’s susceptibility to a substance, affect whether a person will develop cancer,” the statement said.
Substances are listed after being nominated for inclusion, which triggers an exhaustive evaluation of the scientific evidence and public input.
The new report adds the following substances as known carcinogens:
* Formaldehyde, which was listed in the second report as a substance that was “reasonably anticipated to be a human carcinogen” based on studies showing it caused nasal cancer in rats. In addition to being used as a preservative in medical laboratories, it is widely used to make resins for household items, such as composite wood products, paper product coatings and plastics. It is also in some consumer products, such as hair-straighteners.
“There is now sufficient evidence form studies in humans to show that individuals with higher measures of exposure to formaldehyde are at increased risk for certain types of rare cancers,” including cancer of the throat and a cancer of white blood cells known as myeloid leukemia, the announcement states.
* Aristolochic acids, which is a family of acids that occur naturally in some plants and so are found in some herbal remedies. The Food and Drug Administration in 2001 warned consumers against using any products containing the acids, but they are still sold on the Internet and are found in herbal products used to treat a variety of conditions, including arthritis, gout and inflammation. The acids can cause bladder and urinary tract cancer in people with kidney or liver disease, the agency said.
The six substances now considered to be “reasonably anticipated” to be a carcinogen are:
* Styrene, which is a synthetic chemical used to make products such as rubber, plastic, insulation, pipes, car parts, food containers and carpet backing. In addition to being found in cigarette smoke, the average person can be exposed by “breathing indoor air” containing vapors from building materials and other products. Workers can also be exposed in industrial settings. Studies involving people and animals indicate it can cause genetic damage to white blood cells.
* Captafol, which is a fungicide used to control fungal diseases in fruits, vegetables, plants and grasses. It has been banned in the United States since 1999, but past exposures may still affect people. It has been linked to various types of tumors.
* Cobalt-tungsten carbide, which is used to make cutting and grinding tools and other products used in many industries, including oil and gas drilling and mining.
* Inhalable glass wool fibres found in home and building insulation.
* O-Nitrotoluene, which is used to make dyes for fabrics, leather and paper as well as agricultural chemicals, rubber chemicals, pesticides and explosives.
* Riddelliine, which is also found in some herbal medicines, including teas. It has been found to cause cancer of the blood vessels in rats and mice, leukemia and liver cancer in rats and lung tumors in mice.