clean-sink-cp-306

Bleach-based products proved the most successful in lowering the concentration of noroviruses, according to a new study. ((Beth Hall/Associated Press))

As many as 40 per cent of commercial disinfectants may be ineffective in killing the viruses that cause the stomach flu, according to a new study released by Laval University researchers.

Lead researcher Julie Jean compared the efficacy of bleach-based products, alcohol-based cleansers and quaternary ammonium-based disinfectants in combating noroviruses. The bleach-based products proved the most successful in lowering the concentration of the viruses, according to the study published in the Journal of Food Protection.

"Our results are of particular concern considering that some 40 per cent of the commercial surface disinfectants on the market are alcohol- or ammonium-based," Jean said in a release.

Tests showed that using a bleach-based disinfectant for five minutes lowered the concentration of noroviruses on a stainless steel surface by a factor of 1,000. By comparison, the other cleansers were 100 times less effective.

The researchers also note that human noroviruses can latch onto a stainless steel surface within 10 minutes and survive for weeks.