The Office for Consumer Protection and Veterinary Affairs for the Canton of St. Gallen in Switzerland is reported to have found paper drinking straws contaminated with chloropropanols, mineral oil hydrocarbons, and photoinitiators. The Cantonal laboratory officially acquired twelve paper straws from various supermarkets, warehouses, restaurant suppliers, online stores, and restaurants across Switzerland. Each straw was tested first for paper quality by placing it in water at a temperature of 70 degrees Celsius for two hours and then analyzing concentrations of extracted substances using gas chromatography. Migration of substances into food was then tested following the same approach but using solutions of 3% acetic acid and 50% ethanol to simulate contact with lemonade and milk, respectively. Of the twelve paper straws tested, seven (58%) had elevated concentrations of dichloropropanol (CAS 26545-73-3) and/or 3-monochloropropane-1,2-diol (CAS 96-24-2), two (17%) were contaminated with mineral oil hydrocarbons, two (17%) showed migration of photoinitiators into the food, and six (50%) were found to change the taste of the drink.
Chroropropanols can be carcinogenic, and they can be formed during the paper’s production. Mineral oil hydrocarbons exist as different fractions, can be carcinogenic and mutagenic, and can enter food contact materials as intentional additives, through printing inks, through contact with processing equipment, or through recycling and using previously contaminated paper. The primary source of photoinitiators is printing inks.
EU Directive 2019/904 bans many single-use plastic products in the EU from 2021, including plastic drinking straws (FPF reported). This is leading many manufacturers to produce paper drinking straws as an alternative. In April 2018, Swiss authorities reported on elevated concentrations of mineral oils and chlorinated substances found in paper and board packaging (FPF reported).
Nina Rudnicki (July 24, 2019). “Für einen Sirup ohne Beigeschmack – in St.Gallen werden Trinkröhrli aus Papier auf verschiedene Giftstoffe untersucht.” Tagblatt (in German)
SRF News (July 24, 2019). “Trinkröhrli aus Papier mit fahlem Beigeschmack.” (in German)
TOP Online (July 23, 2019). “Kanton St.Gallen unterzieht «Papierröhrli» einem Härtetest.” (in German)
Chemical Watch (August 7, 2019). “Suspected CMRs found in Swiss paper drinking straws.”