Factors influencing the leaching of heavy metals from plastic materials used in the packaging of food and biomedical devices

Effect of various factors such as temperature, sunlight, pH, chemical nature of extracting media and duration of storage on the leachability of heavy metals (Mn, Cd, Cr, Zn and Cu) from commonly used plastic materials were studied using guide lines laid down by ISI, British Plastic Federations and British Pharmacopoeia. Among the various factors sunlight and acidic pH influenced leaching of most of the metals in large quantities. The concentrations of all the metals leached out were found to be above the permissible limits. The amounts of Cd, Cr and Pb leached out were higher than the recommended daily intake values and tolerance levels in drinking water for human beings.