In an emergency, you tend to forget even the most common things. Having emergency phone numbers for the fire, police, and local ambulance by every phone is a very important reminder.
Don't obstruct this vital information with other posted notices around the phone. If your phone is an intercom, it's still important to have emergency information by so that anyone can use it effectively in the event of an emergency.
Providing extra phone number stickers to your employees, faculty, staff, and students is another good way to extend that safety program beyond the workplace.
What should you do if you have no phone? One relatively inexpensive solution might be a pair of wireless intercoms. Another good practice is to train employees as emergency responders. They would know where to go and who to speak to in an emergency.