RESUMO
Objective To study the efficacy and toxicity of tetrakis(hydroxymethyl)phosphonium sulfate(THPS)in indoor air disinfection.Methods The orthogonal experiments were employed with three factors including concentration of THPS,temperature and time,and four levels including the concentrations of THPS,0.05%,0.1%,0.5%,1%,and the temperature,15℃,20℃,25℃,30℃,and the time,2 h,4 h,8 h,16 h.The germicidal effect of THPS with those factors was assessed.Using modified method,Daphnia magna straus(Cladocera crustacea),Brachydanio rerio,mice were randomly divided into 5 dose groups and a control respectively.For Daphnia magna straus(Cladocera crustacea),123.03 mg/L,134.90 mg/L,147.91 mg/L,162.18 mg/L and 177.83 mg/L,for Brachydanio rerio,42.66 mg/L,57.54 mg/L,77.62 mg/L,104.71 mg/L and 140.90 mg/L,for mice,183.60 mg/kg,293.75 mg/kg,470.00 mg/kg,752.00 mg/kg and 1 203.20 mg/kg.The data for 2th,4th and 7th day of treatment were collected for calculation of the 48h-EC50,the 96h-LC50 and the acute oral LD50 in Daphnia magna straus(Cladocera crustacea),Brachydanio rerio and mice.Results The maximal germicidal rate of THPS in indoor air was over 86%.At the concentration of 0.5% THPS,4 h reaction time,germicidal efficacy of THPS was optimal.The toxicity test indicated that the acute oral LD50 for mice was 492.72 mg/kg,the 48 h-EC50 for Daphnia magna straus(Cladocera crustacea)was 143.61 mg/L,the 96h-LC50 for Brachydanio rerio was 84.17mg/L.Conclusion The toxicity of THPS is low and can be used for indoor air disinfection with a good efficacy and the potential benefit for environment.