Face shields are not a replacement for a face mask.
Face shields when masks are not an option
- When communicating using lip-reading, when visual facial cues are essential, or when people may be unable to wear a mask due to a medical condition, a face shield may be an alternative to no mask.
- Some face shields may provide better protection than others. When needed, use face shields that wrap around your face and extend below the chin as well as hooded face shields.
- Non-medical clear masks that cover the nose and mouth are another option when visual communication is necessary. These options have not been widely assessed for their effectiveness.
Source: http://www.bccdc.ca/health-info/diseases-conditions/covid-19/prevention-risks/masks