VALIDATION STUDIES OF A QUICK TEST FOR PREDICTING THE SORPTION AND WASHING PROPERTIES OF REFILLABLE PLASTIC BOTTLES

Quick tests are proposed in the literature as alternatives to the larg e scale contamination and washing studies performed to elate to assess the acceptability of plastic beverage bottles for refilling. These te sts use small plastic specimens ('strips') in place of bottles and use mixtures of surrogate contaminants to model the myriad of chemicals t hat could in principle contaminate returned bottles because of consume r mis-use. The work reported here has measured the sorption and wash p erformance using the quick test protocol with PET (polyethyleneterepht halate) strips and laboratory washing and compared the results with te sts using actual bottles and a commercial washing process. The compari son indicates that the quick test satisfactorily simulated contaminati on and commercial washing of intact bottles. The results also show tha t repeated washing of PET bottles does not cause higher sorption of co ntaminants.