"There is now sufficient evidence from 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 nasopharyngeal ( the upper part of the throat behind the nose), sinonasal, as well as a specific cancer of the white blood cells known as myeloid leukemia," the report said.
"Formaldehyde is a colorless, flammable, strong-smelling chemical that is widely used to make resins for household items, such as composite wood products, paper product coatings, plastics, synthetic fibers, textile finishes, preservative in medical laboratories, mortuaries, as well as some consumer products such as hair straightening products."
Aristolochic acids were listed as a known human carcinogen. In 2001 the U.S. Food and Drug Administration advised to discontinue use of products containing aristolochic acids found as a contaminant in herbal products used to treat arthritis, gout and inflammation that can be purchased online or abroad.
The 12th Report on Carcinogens, available at ntp.niehs.nih.gov/go/roc12, also lists captafol, cobalt-tungsten carbide in powder or hard metal form, certain inhalable glass wool fibers, o-nitrotoluene, riddelliine and styrene as substances that are reasonably anticipated to be human carcinogens.
The Report on Carcinogens, a congressionally mandated report prepared by the National Toxicology Program, identifies agents, substances, mixtures or exposures known or reasonably anticipated to be human carcinogens.