Current Guidance on Face Masks
The guidance consistently advises that for general use by the public where social distancing can be maintained wearing face coverings (surgical masks or cloth coverings) provides very little protection to the wearer. This is not the case for medical staff or carers who deal with known or suspected cases of Coronavirus. For such staff, effective surgical masks or filtering respirators is advised.
All the guidelines stress that face masks on their own, do not provided sufficient protection and they must be supplemented by personal hygiene measures and high standards of workplace cleaning.
However, it is accepted that face masks and cloth face coverings worn by the public reduces the likelihood of the spread of Covid-19 from people who are infected (with or without symptoms). The normal expectation for this community protection is that 90-95% of people in a confined space or in close proximity to each other need to wear a face mask or face covering to give sufficient protection to the potentially exposed community.
The WHO recently changed its advice on the use of face masks and cloth face coverings. It now recommends that surgical face masks should be worn by all staff in hospitals for the whole of their working shifts, with the exception of office-based staff. Importantly, it also now advises that face masks or cloth face coverings should be worn by the general public in situations where it is not possible to maintain at least 1m social distancing. The UK Government reflected these changes in its own advice and rules for hospitals and travelling on public transport. The latter is assumed to take account of the difficulty to maintain social distancing at peak times on public transport.
The likely advantages of the use of masks by healthy people in the general public include:
- reduced potential exposure risk from infected persons before they develop symptoms;
- reduced potential stigmatisation of individuals wearing masks to prevent infecting others (source control) or of people caring for COVID-19 patients in non-clinical settings; making people feel they can play a role in contributing to stopping the spread of the virus;
- reminding people to be compliant with other measures (e.g., hand hygiene, not touching nose and mouth). However, this can also have the reverse effect (see below);
- potential social and economic benefits. Fabric masks can also be a form of cultural expression, encouraging public acceptance of protection measures in general. The safe re-use of fabric masks will also reduce costs and waste and contribute to sustainability.
The likely disadvantages of the use of masks by healthy people in the general public include:
- potential increased risk of self-contamination due to the manipulation of a face mask and subsequently touching eyes with contaminated hands;
- potential self-contamination that can occur if nonmedical masks are not changed when wet or soiled. This can create favourable conditions for microorganism to amplify;
- potential headache and/or breathing difficulties, depending on type of mask used;
- potential development of facial skin lesions, irritant dermatitis or worsening acne, when used frequently for long hours;
- difficulty with communicating clearly;
- potential discomfort;
- a false sense of security, leading to potentially lower adherence to other critical preventive measures such as physical distancing and hand hygiene;
- poor compliance with mask wearing, in particular by young children;
- waste management issues; improper mask disposal leading to increased litter in public places, risk of contamination to street cleaners and environment hazard;
- difficulty communicating for deaf persons who rely on lip reading;
- disadvantages for or difficulty wearing them, especially for children, developmentally challenged persons, those with mental illness, elderly persons with cognitive impairment, those with asthma or chronic respiratory or breathing problems, those who have had facial trauma or recent oral maxillofacial surgery, and those living in hot and humid environments.
The WHO guidance goes on to say that if masks are recommended for the general public, the decision-maker should:
- clearly communicate the purpose of wearing a mask, where, when, how and what type of mask should be worn. Explain what wearing a mask may achieve and what it will not achieve, and communicate clearly that this is one part of a package of measures along with hand hygiene, physical distancing and other measures that are all necessary and all reinforce each other;
- inform/train people on when and how to use masks safely (see mask management and maintenance sections), i.e. put on, wear, remove, clean and dispose;
- consider the feasibility of use, supply/access issues, social and psychological acceptance (of both wearing and not wearing different types of masks in different contexts);
- continue gathering scientific data and evidence on the effectiveness of mask use (including different types and makes as well as other face covers such as scarves) in non-health care settings;
- evaluate the impact (positive, neutral or negative) of using masks in the general population (including behavioural and social sciences).
The latest advice on the protection afforded by the use of face masks for general use by the public was issued by the World Health Organisation, WHO, on 5 June 2020. Other advice and guidance on the use of face masks in a working environment has been published by the UK Government in its sector guidelines on working under Covid-19, The European Commission, , Occupational Health and Safety Organisation, OSHA and by other organisations.