Hairdressers whose businesses have opened up again since this weekend need to be careful using hairdryers, to prevent the possible spread of Covid-19 in salons.
That’s the advice of the Superior Health Council (SHC), in a wide-ranging document issued today covering ventilation, air filtration and air conditioning to prevent the spread of Covid-19.
The document is principally concerned with aerosol transmission of the virus, now considered the main vector of transmission. Aerosols in this context means simply the droplets produced when a person coughs or sneezes, and even when singing or talking loudly. These droplets carry the virus, and can stay in the air for more or less time depending on the conditions.
The prevention of aerosol transmission is one of the main reasons for wearing a face mask.
While the majority of the Council’s advice concerns the treatment of air in building systems, one chapter deals in particular with hand-dryers, and one with hair-dryers.
Hand-dryers that use warm air or jets of air have, according to some studies, been shown to reduce the number of bacteria on the hands. However they also have a tendency to create aerosols of bacteria present in the vicinity, which can then be inhaled.
The report cites one study that showed jet air dryers were most likely to create aerosols – 4.5 times more likely than the standard warm air dryer, and 27 times more likely than paper towels.
When it comes to hair-dryers the report states that the danger of spreading aerosols to others in the vicinity is “not negligible,” but then goes on to state that “There are no reports in the literature of cases of contamination found in a hairdressing salon”.
In fact, the only published case concerning a hairdressing salon reports how two hairdressers in Springfield, Missouri who were themselves infected managed to serve 139 clients with not a single case of infection as a result.
As a precaution, the report says, some countries have banned the use of hair-dryers, not only in hairdressing salons, but also in gyms and the changing rooms of swimming pools.
“In the absence of accurate data, the SHC recommends caution,” the report concludes.
“As in all establishments open to the public, but certainly in establishments of this kind where physical distance cannot be respected and where people can spend several hours, an efficient ventilation system is essential. Moreover, the air quality should be monitored by means of CO2 sensors.”
It then goes on to restate the message of the importance of the main hygiene precautions.
“It is imperative to apply the classic measures: wear a face mask, regularly disinfect surfaces, open doors and windows regularly, even when there is a ventilation system, limit the number of clients in relation to the size of the salon, and respect the safe distance between clients. The hairdresser must also handle the hair-dryer so that the air is not blown from one person to another.”