For researchers handling biohazards, respirators are generally recommended for which Risk Group?

Respirators are generally recommended for researchers handling biohazards classified in Risk Group 3 or 4 because these groups include pathogens that can cause serious or potentially lethal diseases in humans. Risk Group 3 agents can cause serious illness but typically do not spread through casual contact, while Risk Group 4 agents carry a high risk of transmission and are often associated with high mortality rates.

Using respirators in these contexts helps mitigate the risk of inhalation exposure to pathogens that can be transmitted via aerosols or droplets. Proper respiratory protection is essential when working with such highly infectious agents, as it plays a critical role in ensuring the safety of researchers and preventing the potential spread of these dangerous pathogens to others in the laboratory or the community.

In contrast, the lower risk groups, such as Risk Group 1 and 2, do not typically require respirators because the microbes in these groups are associated with minimal or moderate risk of disease, making standard laboratory safety practices and personal protective equipment sufficient for protection.