trihalogenated

Trihalogenated is a chemical descriptor used for compounds in which three halogen atoms have been incorporated into a molecule. The term is commonly applied to organohalogen compounds in which three hydrogens of a hydrocarbon are replaced by halogen atoms—fluorine, chlorine, bromine or iodine—yielding species such as CHX3. The most familiar examples are trihalomethanes, a class that includes chloroform (CHCl3), bromoform (CHBr3), and mixed-halogen variants such as CHCl2Br and CHClBr2.

Trihalogenated compounds occur in nature and from human activity. In environmental chemistry, trihalomethanes form as disinfection byproducts when chlorine or bromine reacts with natural organic matter in water. They are subject to regulatory limits in drinking water due to potential carcinogenic and other health effects. In industry, tri-halogenated methanes and related tri-halogenated hydrocarbons serve as solvents, intermediates, flame retardants, or refrigerants, though many are restricted or phased out because of toxicity and environmental persistence.

Key properties vary with halogen composition. Many tri-halogenated methanes are relatively volatile and denser than water, with limited biocompatibility. Health concerns include carcinogenic potential; exposure can occur via drinking water, air, or occupational settings. Safety data sheets classify several compounds as hazardous, requiring appropriate handling and emission controls.

See also: organohalogen compounds, halogenation, trihalomethane, disinfection byproducts.