Breathing apparatus were created to provide a user with an independent supply of breathable air. S.C.U.B.A. (self- contained underwater breathing apparatus) gear is for underwater use, while work or emergency situations may require the use of gas masks or oxygen masks. There are a few categories used to describe the many types of breathing apparatus available.
Self-Contained Breathing Apparatus
A self-contained breathing apparatus, also referred to as a compressed air breathing apparatus, is often worn by fire or emergency work crews. A SCBA is comprised of a hose, a high pressure air tank, a regulator and a mouthpiece or mask. When a SCBA is used underwater, the acronym becomes SCUBA (self contained underwater breathing apparatus).
Closed-circuit SCBAs filter, supplement and re-circulate exhaled gas. Closed-circuit apparatus is typically used in environments in which bulky additions, such as a tube or high pressure air tank, would not be allowed. A mine rescue operation would call for a closed-circuit apparatus or re-breather, due to narrow passageways and time constrictions for a set air supply. Modern re-breathers or industrial breathing sets include the Biopack, which can be used for one to four hours.
Open-circuit SCBAs or industrial breathing sets use filtered, compressed air, which is exhaled by the user. Once the air is exhaled, the amount of air available to the user is diminished, so there is a time limit. Open-circuit apparatus utilize air cylinders or canisters which can have anywhere from 30 minutes to one hour of air available.
Medical Breathing Apparatus
Breathing apparatus such as ventilators or respirators is critical to keeping distressed or injured newborns and infants alive. Ventilators and respirators are also used for elderly or injured patients who are having problems breathing on their own. Ventilators are machines that assist patients with breathing by using a tube placed into the windpipe; the air is mechanically moved in and out of the lungs when a patient cannot inhale or exhale oxygen.
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