Investigation of xylene permeability as pesticides and herbicides solvent in ‎cylindrical plastic bottles ‎

The permeability of agrochemical contents through typical plastic bottle walls has been investigated. There were four different formulations of abamectin used in this study, consisting of 1.8% abamectin as sample 1, 3.6% abamectin as sample 2, 0% abamectin as sample 3 (just containing abamectin ‎solvent system and emulsifier), and 1.8% abamectin with double emulsifier as sample 4. The pesticide composition had a significant effect on multi-layer plastic bottle wall permeability at room temperature. The maximum permeability is related to sample 3 at 54°C with a mass ‎flux of 0.21 gr/m2.day. The mass flux of sample 3 was about 3.7 times higher at 54°C compared to room ‎temperature. Since xylene is the main solvent of pesticides (i.e. abamectin), it was selected as a migrating component in all types of bottles. The main experiments in the second step have been done with thick PET (0.9 mm thickness), ordinary PET bottles (0.35 mm thickness), single-layer PE, co-extruded PE bottles with different barrier layers including EVOH, PA6, and PA6/6.6 co-polymer. For 45 days and 54°C, the EVOH-based bottle has the least permeability compared to the other bottles with a mass ‎flux of 0.25 gr/m2.day. The PA6 and PA6/6.6-based bottles in the same condition have 5% and ‎‎65% more xylene permeability, respectively. Thick PET bottles, The single-layer PE bottle and ordinary ‎PET were not suitable for xylene maintenance and collapsed after a few days.‎