Evaluation of the Toxic Effects of Waste Liquid Crystal Displays (LCD) to the Environment

Different samples of LC-displays and 6 mixtures of liquid crystals mixtures were tested for toxic effects by using standard procedures in aquatic toxicology. LCD were crushed and subject to aequous elution and extraction with hexane; LC-mixtures were shaken with water or DMSO to obtain saturated aqueous and organic phases. Biological testing mainly employed a test for inhibition of luminescence with V. fischeri and in addition growthinhibition with V. fischeri and P. putida and the daphnids-test. Toxic effects were found both with LCD and LCmixtures. The toxicity greatly differed between individual LC-mixtures and the different samples of LCD. Mostly the aqueous elutriates were less effective than the organic extracts. Among the biological test luminescenceinhibition reacted extraordinarily sensitive. The results of this study which are based on a very limited number of samples do not allow any general statements on environmental hazards from LCD.