Acute toxicity to fish and solution stability of some biocides used in the pulp and paper industry

Acute toxicities of four biocide compounds and their formulations to rainbow trout have been determined. The 96-hour LC50 values of bis-trichloromethyl-sulfone (BTMS), β-bromo-β-nitrostyrene (BNS), methylene-bis-thiocyanate (MBT), and a mixture of isothiazolinones (ISO) were 0.02, 0.05, 0.09, and 0.2 ppm, respectively. Stabilities of individual compounds in an effluent and in aqueous solution have also been investigated. The results show that BNS and MBT were not stable, BTMS volatilized into the open atmosphere, and ISO remained stable under the experimental conditions employed.