Doctors, scientists and public health experts have called on the World Health Organization (WHO) to recommend wearing respirators at every encounter in all healthcare facilities. In the letter, seen by The BMJ, they are calling for infection prevention and control guidelines to be updated so that healthcare workers use respirators such as N95, FFP2/3 and elastomeric masks. The letter's authors call the fact that respirators are not standard practice "scientifically indefensible" and "dangerous." They argue that the current state of affairs puts staff and patients at avoidable and potentially fatal risk from pathogens such as SARS-CoV-2. Approximately 50 experts signed the letter. Among the signatories are Martin McKee, professor of European public health at the London School of Hygiene and Tropical Medicine, and Trisha Greenhalgh, professor of primary health science at the University of Oxford.