Human infections with novel influenza A viruses (such as H5N1 Bird Flu) can happen when enough virus gets into a person´s eyes, nose, or mouth, or is inhaled. This can happen when virus is in the air (in droplets, small aerosol particles, or possibly dust) and deposits on the mucus membranes of the mouth, eyes, or nose. It can also happen when a person breathes the virus in, or possibly when a person touches something contaminated by viruses and then touches their mouth, eyes, or nose.

Employers should take steps to reduce workers´ exposure to novel influenza A viruses from sick animals or contaminated environments. Workers may be exposed when working with animals confirmed or potentially infected with novel influenza A viruses. They may also be exposed when working with materials, including raw milk, that are confirmed or potentially contaminated with novel influenza A viruses. Examples of related workers include:

Poultry and dairy and other livestock farmers and workers
Backyard bird flock owners
Veterinarians and veterinary staff
Animal health responders
Public health responders
Dairy laboratory workers
Food processing workers handling raw milk and other confirmed or potentially contaminated materials
Slaughterhouse workers performing certain tasks on lactating dairy cattle including:
Unloading or handling live lactating dairy cattle for slaughter, including working in holding pens and tasks involved with ante-mortem inspection
Post-mortem processes including the post-mortem inspection, handling, and transporting of viscera
Removing and transporting udders from dairy cattle for further processing or rendering
To protect workers who might be exposed, employers should update or develop a workplace health and safety plan. Employers are encouraged to use a health and safety committee that includes representatives from both management and workers to develop the plan. Helpful guidance and consultation on developing a workplace health and safety plan is available from the Occupational Safety and Health Administration (OSHA) and through your local agriculture extension office. Employers in a state regulated by a state OSHA plan should familiarize themselves with any additional requirements that may apply to them. Employers should conduct a site-specific hazard assessment to identify potential exposures based on work tasks and locations and use the hierarchy of controls to identify controls to reduce or eliminate hazards including exposure to novel influenza A viruses. The Hazard Assessment Worksheet for Dairy Facilities can help identify dairy workplace hazards and prioritize controls including personal protective equipment (PPE) needed for protection. Protecting Poultry Workers from Avian Influenza (Bird Flu) can help identify poultry workplace hazards and prioritize controls. CDC provides separate recommendations to prevent the spread of flu between pigs and people.

The hierarchy of controls identifies a preferred order of actions to best control hazardous workplace exposures. Engineering controls are more effective than administrative controls or PPE because they control exposures without requiring significant and ongoing efforts by workers and their supervisors. The following table identifies the type of controls that can be used based on our current understanding of the exposure risk associated with different work tasks and settings.