The isolation, separation and identification of carcinogenic and noncarcinogenic polycyclic aromatic hydrocarbons (PAH) from furnace semireinforcing carbon-black (7440440) was investigated. The carbon-black was extracted by 24 hour distillation in benzene, evaporated to dryness, and placed in a gas chromatograph with dual columns and dual thermal conductivity and flame ionization systems at 200 to 250 degrees-C. A spectrophotofluorometer recorded emission and excitation spectra of peaks which were collected and the ultraviolet (UV) spectrum recorded in a UV absorption spectrophotometer. The PAHs were quantitated and identified as follows: the known animal carcinogens 1,2-benzanthracene (56553), 9,10-dimethyl-1,2-benzanthracene (57976), 3,4-benzopyrene (50328), and ortho-phenylene-pyrene (193395); and the noncarcinogens anthracene (120127), anthanthrene (191264), phenanthrene (85018), fluoranthrene (206440), benzo(mno)fluoranthrene (203123), chrysene (218019), 1,2-benzopyrene (192972), perylene (198550), 1,1,2-benzoperylene (191855), and coronene (191071). The authors conclude that spectrophotofluorometry can provide high accuracy in identification of PAHs in carbon-black. The carcinogenicity of carbon-black and its potential occupational cancer hazard in industry has still not been proven.