Prof Ron Eccles, former director Common Cold Centre at Cardiff University, criticised the study and said the suggestion that the virus could survive for 28 days was causing "unnecessary fear in the public".
"Viruses are spread on surfaces from mucus in coughs and sneezes and dirty fingers and this study did not use fresh human mucus as a vehicle to spread the virus," he said.
"Fresh mucus is a hostile environment for viruses as it contains lots of white cells that produce enzymes to destroy viruses and can also contain antibodies and other chemicals to neutralise viruses.
"In my opinion infectious viruses will only persist for hours in mucus on surfaces rather than days."