ABSTRACT
Toners are powdered inks. Printing is widely used in our society to pass on information, for documentation and to decorate objects. In recent times paper and paperboard is being used in food packaging. Some of these packages are printed on with printing inks. Heavy metals can be present in printing toners in the form of pigments or through impurities and contamination in raw materials. Heavy metals in printing toners are hazardous and non-biodegradable, thus, in a period of time accumulates and deteriorates the human health, the land it settles or gathers on and the water it flows in. This work was directed towards the investigation and analysis of printing toners. The samples of printing toners were taken for four (4) different brand from printing cafes/press in Benin City, Nigeria. A total of sixteen samples were collected and digested with acid for heavy metal analysis using atomic absorption spectrophotometer. The heavy metals analysed were lead (Pb), chromium (Cr), cadmium (Cd) and zinc (Zn). In Brand – A, the mean concentration of heavy metals are 0.078mg/kg Cr, 0.02mg/kg Pb, 0.025mg/kg Cd and 0.303mg/kg Zn. In Brand – B, the mean concentration of heavy metals are 0.048mg/kg Cr, 0.0075mg/kg Pb, 0.00mg/kg Cd and 0.335mg/kg Zn. In Brand – C, the mean concentration of heavy metals are 0.088mg/kg Cr, 0.023mg/kg Pb, 0.025mg/kg Cd and 0.420mg/kg Zn. In Brand – D, the mean concentration of heavy metals are 0.07mg/kg Cr, 0.035mg/kg Pb, 0.00mg/kg Cd and 0.450mg/kg Zn.
The various values were compared with the 94/62/EC permissible limit for printing toners and they were all found below limit except for chromium and zinc which was not available.
