The Effect of Multiple-use of Polystyrene Cups on Styrene Monomer Migration

Traces of styrene monomer are normally foWld in polystyrene (PS) Cl\PS due to
incomplete reaction during their processing. This study was conducted to investigate the
effect of multiple-use on styrene monomer migration from PS cup into the foodstuff it
contained. Palm oil and distilled water were used as stimulants to promote the migration
of styrene from the cups and to simulate the fatty and aqueous medil\ill of beverages
respectively. The cups were repetitively exposed to the stimulants at 1 00°C up to ten
times. The stimulants were then tested for their styrene monomer content using gas
chromatography-mass spectroscopy (GC-MS) technique. Analysis by GC-MS showed
that styrene monomer was detected in the palm oil stimulant but undetected in the
distilled water when the cups were subjected to repetitive use. The maximl\ill
concentration of styrene monomer measured in the palm oil was 161.74 ppb after the 6th
repetition while the miniml\ill level was 16.14 ppb measured after the gth repetition. The
maximl\ill value of 161.74 ppb is exceeding the limit of WHO guideline value which
might be harmful to the consl\iller under prolong and continuous exposure. The study
has highlighted the negative effect of using PS cup repetitively especially in the
presence of fatty medil\ill. The effect may not be as bad if the cup contained only
aqueous medium