OSSAMONIO® PQA-21 is a polymeric quaternary ammonium compound based on Polyquaternium-42 (polyquaternium chloride), formulated as a viscous amber aqueous solution. It is characterized by its cationic polymeric structure, which provides high affinity for surfaces and prolonged action in aqueous systems.

It stands out for its effectiveness as a broad-spectrum biocide, acting as an algaecide, bactericide, and molluscicide, enabling efficient control of biological growth in various applications. Its polymeric nature results in lower volatility and greater persistence compared to low molecular weight quaternary compounds.