This guidance aims to expand and explain the legal requirements for working with high-hazard pathogens, with a particular focus on the way in which these requirements influence the design, construction and operation of CL4 facilities. This
guidance is intended for all laboratories in which high-hazard pathogens, including viral haemorrhagic fiver, Hendra and Nipah viruses, herpesvirus simiae (B virus) and Varols (smallpox), may be handled.