As we "ring" in the new year, the U.S. Department of Labor Occupational Safety
& Health Administration (OSHA) wants to call to your attention to another
"ringing" of great importance to our daily working lives - the sound of
emergency alarm systems. Here are some suggestions for guaranteeing that your
workplace has adequate means of alerting its employees in the event of an
emergency:

• Ensure that employee alarm systems are recognizable and perceptible in every
  location during emergency conditions.
  
• Instruct employees on the location of alarm pull boxes.
  
• Train employees on all alarm and evacuation procedures and conduct periodic
  drills.
  
• Post emergency phone numbers, including the numbers for the local fire
  department, hospitals and ambulances, police department, plant emergency
  services, fire brigade, or health center (if provided).

more info

AplusA-online.de - Source: U.S. Department of Labor Occupational Safety & Health Administration