City’s watchdog says most disinfectants not as good as claimed

A majority of fancy disinfectants do not work as well as old-school diluted bleach or alcohol in killing germs, Consumer Council has found.

The watchdog tested 15 models of multi-purpose disinfectants and found 80 percent to fail to match performance of 75 percent alcohol-based preparation and bleach diluted with water in a 1:99 ratio.

Amongst them, the worst performers were two chlorine dioxide-based models _ one from Taiwan and one from Japan _ with a disappointing kill rate of less than 28 percent in two bacteria tests, Escherichia coli K12 and Staphylococcus aureus – the former lives in your intestines, and the later in upper respiratory track and can cause pneumonia. But the sample from Taiwan claimed that it can kill 99.99 percent of bacteria.  

Meanwhile, diluted bleach and 75 percent alcohol solution have a kill rate of 99.999 percent for the test bacteria, and reduction of viral infectivity of 87.98 percent and 99.83 percent respectively.

Nine models which claimed that they can eliminate 99.9 percent to 99.999 percent viruses failed to meet their claim in virucidal efficacy in the test.
 
Three samples _ SanitCare Plus+ from the United States, TOAMIT from Japan, and local brand AQ Bio Sanitizer could not reduce the viral infectivity of Adenovirus type 5 in a short period of time. 

Chairwoman of the council’s research and testing committee Nora Tam Fung-yee said people should avoid spraying the disinfectants on their body directly.