Zerohalogen

Zerohalogen is a descriptor used in materials science and industry to indicate that a material or product contains no halogen elements—specifically fluorine, chlorine, bromine, iodine, or astatine—in its base polymers or additives, within defined limits. It is not a chemical compound, but a labeling convention intended to signal reduced potential for toxic or corrosive fumes when burned. The term is most commonly encountered in flame-retardant polymers and electrical cable coatings.

Scope and terminology: Zerohalogen is closely related to “halogen-free” and to “low-smoke zero-halogen” (LSZH) classifications. Because there is no universal standard for all industries, zerohalogen claims are defined by manufacturers or by customer-specific specifications. A claimed zerohalogen material may be designed to be free of halogen-based flame retardants and to minimize halogen content overall.

Testing and verification: Halogen content is usually assessed by elemental analysis, such as X-ray fluorescence, while fire performance is evaluated through standard burning tests and smoke/acid gas measurements. In practice, thresholds vary by jurisdiction and application, and some products may allow trace halogen levels under certain conditions.

Applications and implications: Zerohalogen materials are widely used in electrical cables, connectors, and building materials where reduced halogen content is desired to limit toxic fumes and corrosive residues during combustion. They may require different processing conditions or higher material costs and can trade off mechanical properties or flame performance relative to halogen-containing alternatives.

See also: Halogen-free, LSZH, flame retardants, electrical cables.