In an article published on January 22, 2022, in the peer-reviewed Journal of Hazardous Materials, Selina Tisler and Jan H. Christensen from the University of Copenhagen, Frederiksberg, Denmark, reported on the migration of over 400 plastic-related compounds from reusable bottles into drinking water. The scientists used different types of reusable plastic sports bottles, including some marketed as biodegradable, and performed migration experiments over 24 hours at room temperature in tap water. Using non-targeted liquid-chromatography – high-resolution mass spectrometry (LC-HRMS) they compared the chemicals migrating from newly purchased but rinsed bottles, bottles used for one year, bottles subjected to dishwashing (60 min, 65 °C), as well as bottles thoroughly rinsed with cold water after dishwashing. Tisler and Christensen detected more than 400 plastic- and more than 3500 dishwashing-related compounds. Generally, dishwashing was found to enhance chemical migration, and even when flushing the bottles after dishwashing, over 400 of the 3500 compounds were still detected to migrate. These were especially non-polar compounds. Comparison with glass bottles indicated that dishwashing-related chemicals absorbed better to plastic than glass.
The compounds meeting the researchers’ filtering criteria were compared with Norman lists including the Food Packaging Forum’s database of Chemicals associated with Plastic Packaging (CPPdb, FPF reported), and the 50 highest peaks in each bottle were additionally investigated by using a non-targeted screening workflow. Following this approach, Tisler and Christensen identified 41 compounds with different confidence levels according to Schymanski et al. (FPF reported). The majority of the compounds identified for the new bottles were oligomers of plasticizers “suspected to originate from the biodegradable polyester polycaprolactone, and aromatic amines, which may have been introduced as slip agents or antioxidants.” For the used bottles, migrating chemicals were identified to be plasticizers, antioxidants, and photoinitiators. Photoinitiators have previously been detected in paper straws (FPF reported) and other paper FCMs (FPF reported and here). The photoinitiators identified by Tisler and Christensen included Irgacure 369 (CAS 119313-12-1), known for its endocrine-disrupting properties and added on the REACH registration list as carcinogenic, mutagenic, or toxic to reproduction (CMR; FPF reported), 4-methylbenozophenone (CAS 134-84-9) a carcinogen, as well as anthraquinone (CAS 84-65-1) whose break-down products may also be carcinogenic.
Furthermore, the scientists predicted the bottles’ hazard based on the identified chemicals. Here, the used plastic bottles refilled directly after the dishwashing received the highest hazard ranking. The authors raised “the question whether plastic bottles are suitable for re-use, especially when they are labeled as biodegradable plastics,” since the study results suggest that “plasticizers will migrate more easily into the consumers drinking water when the biodegradable plastic bottles slowly degrade during use.”
Reference
Selina Tisler S. and Christensen J. H. (2022). “Non-target screening for the identification of migrating compounds from reusable plastic bottles into drinking water.” Journal of Hazardous Materials. DOI: /10.1016/j.jhazmat.2022.128331
