What are the key applications and quality specifications for p-chlorophenol in China?

What are the key applications and quality specifications for p-chlorophenol in China?
P-chlorophenol (CAS 106-48-9) is a white crystalline solid with an unpleasant odor; industrial grades appear yellow or pink. It is slightly more acidic than phenol (pKa 9.38 vs 9.94 in water). Major applications span agrochemicals—synthesizing fungicides like 5,5'-dichloro-2,2'-dihydroxydiphenylmethane, plant growth promoters, and insecticides—plus pharmaceuticals including clofibrate and 5-chloro-2-hydroxybenzoic acid sodium salt, and dyes such as 1,4-dihydroxyanthraquinone. It also serves as an antioxidant BHA intermediate and selective solvent for mineral oil refining. Market grades are typically classified by purity: 99% and 99.5% are common commercial specifications, with higher purity commanding premium pricing for pharmaceutical applications.