Microplastics found in contents of glass bottles

Microplastics found in contents of glass bottles

"Drinks including water, soda, beer and wine sold in glass bottles contain more microplastics than those in plastic bottles, according to a surprising study released by France's food safety agency," was the leading sentence of a news item published by Phys.org based on a publication ANSES Laboratoire de Sécurité des Aliments, France.

Microplastic contaminations in a set of beverages sold in France found in beverages packaged in glass are similar to those found for cans and bricks/beverage cartons, and also for plastic water bottles. 

The main source of microplastics in the glass bottled beverages was reported to be paint from closures/caps. When the bottles are filled, the caps are placed by a process where there is potential for mechanical stress/friction, resulting in polyester based paint chips. These paint fragments can then accumulate on the inner side of the caps, and that is how it gets into the bottle. So the source is linked to the filling process and painted caps. Some simple cleaning procedures saw significant reductions in this contamination source.

Glass bottled beverages were also found to contain polyolefin microplastics which could originate from cold-end coatings used to lubricate the passage of the bottles. Levels were higher for wider mouth containers compared to beer, etc. Lowering the spray nozzles would reduce the chances of lubricant residues entering the bottle.

The size of microplastics measured in this study were 30–500 µm, several orders of magnitude bigger than the nanoplastics which have been absorbed into the body.

The glass industry (FEVE) and ANSES are exchanging ideas to gain a better understanding of the problem and work on concrete and effective solutions, some of which have already been considered by the team of researchers behind the study.