Is benzalkonium chloride an acid or base?

Benzalkonium chloride is a quaternary ammonium compound, which means it has a nitrogen atom with four alkyl groups attached. It is a cationic surfactant, which means it has a positive charge. Benzalkonium chloride is a weak base, with a pKa of approximately 12. This means that it can donate a proton to a stronger base, but it cannot accept a proton from a weaker acid.