A substance's inclusion on the federal carcinogen list doesn't… (National Cancer Institute )
Formaldehyde now officially falls into the "known to be a human carcinogen" category. So does the botanical compound aristolochic acid. The U.S. Department of Health and Human Services has updated its Report on Carcinogens, and such were the results.
That report lists compounds -- even biological ones (again, "natural" does not mean "safe," "nontoxic" or "please consume") -- known to increase or strongly suspected of increasing the risk of cancer.
As for styrene, it can now officially be described as "reasonably anticipated" to be cancer-causing. So can captafol, cobalt-tungsten carbide, specific inhalable glass wool fibers, ortho-Nitrotoluene and riddelliine.
The announcement helpfully includes substance profiles, fact sheets and paper trails on all of the above.
The announcement notes: "A listing in the Report on Carcinogens does not by itself mean that a substance will cause cancer. Many factors, including the amount and duration of exposure, and an individual's susceptibility to a substance, affect whether a person will develop cancer."
And as a Bloomberg article points out, for most substances on the report, the risk largely comes from their uses in industry, not personal use.
Formaldehyde, for example, is quite common in the production of building materials and household products, such as pressed-wood products -- particleboard, paneling, cabinets and the like. Styrene is used to make plastics and rubber. But aristolochic acid is found in plants worldwide and is used in herbal supplements. Sometimes, it's simply a contaminant in supplements. The FDA has been warning against it for years now.
Together the additions bring the total of substances you probably want to avoid -- and that the government agrees you want to avoid -- to 240. Again, that's the official list.