In the hygiene laboratory of the Institute for Medical Microbiology and Hospital Hygiene of the University Hospital Frankfurt, it was investigated whether it is possible to hygienically clean SLIDERSTRAWs made of plastic and silicone in household dishwashers so that they can be classified as “harmless” for hygienic reasons. A comparative examination with products of other manufacturers made of glass and stainless steel was also carried out.
Excerpt from the test report:
Material and methods
The hygiene laboratory is accredited as a test laboratory according to DIN EN ISO/IEC 17025:2005 (certificate number D-PL-13102-01 valid until 24.02.2021).
In order to simulate the contamination of drinking straws under realistic conditions, a suspension of commercial tomato juice, the test germ and protein was prepared and thus the SLIDERSTRAWs made of plastic and silicone as well as models made of steel and glass were systematically contaminated on a laboratory scale.
They were then disassembled into the 2 parts, dried and cleaned with the fine program of a household dishwasher. After drying and cleaning of the contaminated SLIDERSTRAWs, a smear was taken, appropriate bacterial cultures were applied and evaluated after the required incubation. The glass and steel straws were treated in the same way. A pre-cleaning with the enclosed brush was not carried out, as this does not seem practical under later gastronomic conditions.
The contamination was carried out with Enterococcus faecium ATCC 19434. Enterococcus faecium is a typical germ of the intestinal flora and a standardized test germ, and is therefore well suited for these investigations.
The program Normal 55°C cleans the SLIDERSTRAWs made of silicone and plastic reliably.
The divisible SLIDERSTRAWs can be cleaned better with the fine program of the dishwasher than the drinking straws made of glass and steel. After rinsing with the fine program, 80% (plastic) and 70% (silicone) of the SLIDERSTRAWs tested are without evidence of the indicator bacteria E. faecium. In the series of tests with glass straws, 50% of the straws examined after rinsing are without detection of the indicator germ E. faecium, and in the series of tests with steel straws, only 20% of the straws are without detection of the indicator germ E. faecium after rinsing.
The present study shows that the tested SLIDERSTRAWs with stronger, dried-on soiling are better cleaned under these conditions than straws made of glass or steel. In addition to our previous expert opinion, this study shows that the separable SLIDERSTRAWs are superior to the glass or steel straws tested here in terms of cleanability.