pdichlorobenzene

Para-dichlorobenzene, also called 1,4-dichlorobenzene (chemical formula C6H4Cl2), is an organochlorine compound and one of three dichlorobenzene isomers. It is a colorless to white crystalline solid with a characteristic sharp odor. It is primarily produced by chlorination of benzene, which yields a mixture of dichlorobenzene isomers that are subsequently separated to obtain the para isomer.

Key properties include a melting point near 53°C and a boiling point around 174°C. It is relatively insoluble in water and miscible with many organic solvents. The compound is moderately volatile and can persist in the environment under some conditions. It is typically handled as a hazardous chemical with precautions to minimize inhalation and skin contact.

Uses and applications of para-dichlorobenzene are varied. It has long been employed as a fumigant and moth repellent in household mothballs and closet deodorizers. In industry, it serves as an intermediate or solvent in the production of dyes, resins, and various chlorinated aromatic compounds. It also appears in some formulations for agrochemicals and other specialty chemicals, where it functions as a building block or precursor.

Safety and environmental considerations are important. Exposure can irritate the eyes, skin, and respiratory tract, and prolonged or high-level exposure should be avoided. The substance is managed as a hazardous chemical in many regulatory frameworks, with guidance emphasizing appropriate storage, handling, and disposal to minimize releases to air, water, and soil. Environmental persistence and potential impacts on aquatic life are noted in safety data literature.

See also: chlorobenzenes, dichlorobenzenes, mothball.