The National Institutes of Health (NIH) has recently added formaldehyde and styrene to the list of known and possible cancer-causing agents. These two compounds have a myriad of uses in consumer products, including plastics and rubbers.
The U.S. Department of Health and Human Services added eight substances to its “Report on Carcinogens,” a document that uses scientific evidence to identify chemicals and biological agents that may put people at increased risk for cancer. With these additions, the “12th Report on Carcinogens” now includes 240 listings. The project is spearheaded by the National Toxicology Program (NTP).
As the NIH press release explains:
The Report on Carcinogens is a congressionally mandated document that is prepared for the HHS Secretary by the NTP. The report identifies agents, substances, mixtures, or exposures in two categories: known to be a human carcinogen and reasonably anticipated to be a human carcinogen.
Several steps are followed to put a substance on the list. If a substance gets nominated by the public or private sector as a possible carcinogen, it goes through an extensive evaluation with numerous opportunities for scientific and public input. For the current list, the NTP got scientific help from several federal agencies, including the NIH, Centers for Disease Control and Prevention, Agency for Toxic Substances and Disease Registry, U.S. Food and Drug Administration, U.S. Environmental Protection Agency, U.S. Consumer Product Safety Commission, and Occupational Safety and Health Administration.
Formaldehyde is listed as a known human carcinogen. It was first listed in the “2nd Report on Carcinogens” as a substance that was anticipated to be aÂ carcinogen, after laboratory studies showed it caused nasal cancer in rats. Now there is sufficient evidence that formaldehyde increases the risks for certain types of rare cancers in humans.
As the NIH press release explains, formaldehyde is a colorless, flammable, strong-smelling chemical that is used to make all kinds of things, such as plastics and synthetic fibers. It’s also well known for its use as a preservative in medical laboratories, mortuaries, and some consumer products, like certain hair straightening products.
Styrene is listed as one of the six substances reasonably anticipated to be human carcinogens. It is a synthetic chemical used in the manufacture of products such as rubber and plastic. The greatest exposure to styrene in the general population, however, is through cigarette smoking.
The report also cites another potential carcinogen that’s used in rubber materials. O-Nitrotoluene is used as an intermediate to make dyes and in preparing industrial and consumer materials, such as rubber chemicals.
An Associated Press report explains the following caveat about carcinogens:
Carcinogens do not always cause cancer. That depends on length and type of exposure and a personâ€™s genetic makeup. The American Cancer Society estimates that only about 6 percent of cancers are related to environmental causes and most of that is on-the-job occupational exposure.
Source: “Government says formaldehyde is cancer-causer and second industrial chemical, styrene, may be,” The Washington Post, 06/11/11
Source: “New substances added to HHS Report on Carcinogens,” NIH News, 06/10/11
Image by PearlyV (Pearl Vas), used under its Creative Commons license.
Rajendrani "Raj" Mukhopadhyay is a science writer and editor who contributes news stories and feature articles on scientific advances to a variety of magazines. Raj holds Ph.D. in biophysics from Johns Hopkins University.