It is not known if PBDEs can cause cancer in people, although liver tumors developed in rats and mice that ate extremely large amounts of decaBDE throughout their lifetime. Lower-brominated PBDEs have not yet been tested for cancer in animals. The International Agency for Research on Cancer (IARC) has classified PBDE as a Group 3 carcinogen (not classifiable as to its carcinogenicity to humans) based on inadequate evidence of carcinogenicity in humans and inadequate or limited evidence in experimental animals. The EPA assigns the cancer category Group D (not classifiable as to human carcinogenicity) to mono-, di-, tri-, tetra-, penta-, hexa-, octa-, and nonaBDEs and reports “inadequate information” to classify the specific congeners 2,2’,4,4’-tetraBDE, 2,2’,4,4’,5-pentaBDE, and 2,2’,4,4’,5,5’-hexaBDE. However, EPA assigns a classification of “suggestive evidence of carcinogenic potential” for decaBDE. The Department of Health and Human Services has not classified PBDEs as carcinogens. The American Conference of Governmental Industrial Hygienists (ACGIH) has no data regarding cancer classifications for PBDEs.