(CNN) -- United States health authorities have added eight commonly used substances to its official "Report on Carcinogens," saying they may put people at increased risk of developing cancer.
The industrial chemical formaldehyde and a botanical substance known as aristolochic acids are listed as "known human carcinogens" while six others, including certain inhalable glass wool fibers and styrene, used in Styrofoam, are listed as substances "reasonably anticipated to be human carcinogen," the U.S. Department of Health and Human Services announced Friday.
Formaldehyde, which was listed on a previous report, was upgraded to "known carcinogen" after it was found to cause nasal cancer in rats. A colorless, flammable chemical, formaldehyde may be found in a wide range of products from plastics, synthetic fibers to hair straightening products and textile finishes.
Aristocholic acid -- a natural-occurring botanical substance -- may cause cancer of the urinary tract and permanent kidney failure, the report stated. It is used in traditional Chinese herbal medicine and in some weight-loss herbal medicines.
Six other commonly used products were listed as "reasonably anticipated to be human carcinogens", including styrene, a chemical found in products such as Styrofoam and fiberglass.
Exposure to captafol, cobalt-tungsten carbide (in powder or hard metal form), certain inhalable glass wool fibers, o-nitrotoluene, riddelliine, and styrene -- are "reasonably anticipated to increase carcinogenic exposure," the report states.