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 large scale contamination and washing studies performed to date to assess the acceptability of plastic beverage bottles for refilling. These tests use small plastic specimens ('strips') in place of bottles and use mixtures of surrogate contaminants to model the myriad of chemicals that could in principle contaminate returned bottles because of consumer mis-use. The work reported here has measured the sorption and wash performance using the quick test protocol with PET (polyethyleneterephthalate) strips and laboratory washing and compared the results with tests using actual bottles and a commercial washing process. The comparison indicates that the quick test satisfactorily simulated contamination and commercial washing of intact bottles. The results also show that repeated washing of PET bottles does not cause higher sorption of contaminants.