Biotesting of melamine using a multi-component test system

Abstract

In recent decades, halogen-containing fl ame retardants have been gradually replaced by safer fl ame retardants, including nitrogen-containing compounds. However, their ecotoxicity is poorly studied. The ecotoxicity of melamine, a widely used nitrogen fl ame retardant, at concentrations equal to MPC in water (4 mg/L), 5 MPC (20 mg/L) and 10 MPC (40 mg/L) was assessed in this study using a complex of test organisms. The assessment of ecotoxicity using the dehydrogenase activity of Dietzia maris AM3 as a test microorganism revealed a stimulating eff ect of melamine at a concentration equivalent to the MPC; concentrations of 5 and 10 MPC inhibited the activity of dehydrogenases by 19.3% and 10.5%, respectively, indicating low toxicity. No toxic eff ects were observed on protococcal algae Chlorella vulgaris Beijer at any of the tested concentrations. The eff ect of melamine solutions on the mortality of crustaceans Daphnia magna Straus was noted only at a concentration of 10 MPC, and the mortality rate was 25%. Lemna growth inhibition test showed that melamine at concentrations equal to the MPC and 5 MPC had an inhibitory effect on the growth of Lemna minor L. It also caused a significant decrease (by 47–52%) in the total chlorophyll content in fronds when exposed to all studied concentrations of melamine.

Keywords

• melamine
• ecotoxicity
• dietzia maris ам3
• chlorella vulgaris beijer
• daphnia magna straus
• lemna minor l.