Air-Supplied
Respirators

Combination Respirators

Self-Contained Breathing Apparatus

• makes use of a hose to deliver clean, safe air  from a stationary source of compressed air
   
• provides clean air for long periods of time and are light weight for the user
   
• limits the range of user-mobility and may fail due to hose damage
   
• also called  airline respirators

• have an auxiliary self-contained air supply that can be used if the primary supply fails
   
• the self-contained portion can be small since it only needs to supply enough air for escape
   
• can be used for entry into confined spaces 

• consists of a wearable, clean-air supply pack
   
• do not restrict movement with a hose connection
   
• the closed-circuit type can provide air up to 4 hours
   
• the open-circuit type only provide air for 30 - 60 minutes

• are normally used when there are extended work periods required in atmospheres that are not immediately dangerous to life and health (IDLH)

• are normally used when there are extended work periods required in atmospheres that are or may be immediately dangerous to life and health (IDLH)

• are normally used when there is a short-time need to enter and escape from atmospheres which are or may be immediately dangerous to life and health (IDLH)

• Employers are required to provide employees using atmosphere-supplying respirators (supplied air and self contained breathing apparatus) with breathing gases of high purity, and shall ensure that compressed air, compressed oxygen, liquid air, and liquid oxygen used for respiration is in accordance with the specifications of OSHA Standard 1910.134(i).