p-Hydroxybiphenyls are used as dyes; Intermediates for resins and rubbers. red light enhancement of p-hydroxybiphenyl synthesis; Green photo-enhancer is one of the main raw materials for color films, and is also used as an analytical test chemicalbook agent. Colorimetric determination of acetaldehyde and lactic acid, quantitative determination of muramic acid. Inhibitors of DNA I enzymes. Intermediates of dyes, resins and rubbers, fungicides, solubilizers for water-soluble paints.