Migration of toxicants from plastics into drinking water during storage

Abstract

In this study, migration of toxicants, such as, manufacturing additives and previously adsorbed materials into drinking water stored inside plastic containers was investigated. The study considered virgin containers as well as those previously used to store sulphuric acid, calcium hypochlorite, methyl ethyl ketone (MEK) and ethanol.
The results showed that drinking water stored in virgin containers desorbed 0.047mg/I of lead, 0.001mg/I of cadmium, and 4.68mg/I of phosphate within 35 days of storage. Lead and cadmium were therefore within FEPA\'s specifications of <0.05mg/I, while phosphate was outside the FEPA\'s range of <0.1mg/I. When ethanol was stored in virgin containers for 18 weeks, benzene and hexane were detected in the ethanol as migrants from the plastic showing that ethanol degraded the plastic thereby causing the release of such components. Tests carried out on reused containers showed that for containers used previously to store sulphuric acid, pH decreased from 7.14 for tap water to 2.23 for stored water after two weeks and sulphate concentration increased from 0.1mg/I in tap water to 2.94mg/I in water stored for two weeks. Iron, lead and cadmium were also above their respective upper limits for drinking water.

Keywords: migration, toxicants, plastics, water, storage

Global Journal of Engineering Research Vol.4 (1&2) 2005: 63-67