The Health and Safety Executive (HSE) is warning against the use of KN95 facemasks as Personal Protective Equipment (PPE).
KN95 is a performance rating that is broadly equivalent to the EU standard for FFP2 facemasks. Products manufactured to KN95 requirements rely on a self-declaration of compliance by the manufacturer, so there is no independent certification or assurance of their quality. Perhaps as a consequence, KN95 masks are often accompanied by fake or fraudulent paperwork.
You can read the full HSE Safety Alert on their Safety and Health Practitioner (SHP) website here.
If you are looking for advice on workplace safety during coronavirus (COVID-19) we recommend that you start with the Government website here.