HSC (SQSD) 19/21 - Infection Risk when using FFP3 Respirators with Valves or Powered Air Purifying Respirators (PAPRs) during Surgical and Invasive Procedures Date published: 28 September 2021 HSC (SQSD) 19/21 Documents HSC (SQSD) 19/21 - Infection Risk when using FFP3 Respirators with Valves or Powered Air Purifying Respirators (PAPRs) during Surgical and Invasive ProceduresAdobe PDF (542.3 KB)