We comply with the HONcode standard for trustworthy health
information:
verify here.


MedEdOnline
Five Richland Medical Park
Columbia, SC 29203
USA
Phone: +1.803.434.7101
Fax: +1.803.434.4354
 

Multiplace Delivery System

Monthly Hyperbaric Safety Notice: April 2006

Individual Breathing Apparatus

In this notice, the individual breathing apparatus for the chamber occupant’s personnel outside the chamber and the breathing gas supply system will be discussed.

Background

Individual breathing apparatus is required for all occupants of a Class A chamber.  The supply of breathing gas must be independent of the chamber atmosphere and the apparatus must work at all chamber pressures.  There must be a secure source of air for the external personnel.

Safety Issue

There have been fatalities in chambers where the atmosphere became toxic or had inadequate oxygen to support life.  Personnel outside of a chamber need to be able to safely decompress and evacuate the occupants of a chamber if the air surrounding the chamber becomes inhabitable.

Every occupant of a Class A chamber needs to have a device that delivers a breathable gas that is not dependent on the chamber atmosphere.  For the patients in the chamber this can be accomplished by the oxygen delivery device (hood, mask, t-piece, ventilator, etc).  We have installed a switching valve that shuts off the oxygen to the chamber and supplies medical air to the patient devices in the event of an emergency.  For the inside attendants apparatus we are using a Survivair model 9815-10.  This is a silicone, 4 point suspension, full face, continuous flow, supplied air respirator (SAR).  The face mask has a speaking diaphragm and a large sealing surface. There are many good SAR’s available, Mine Safety Appliance, Scott and 3M to name a few.  The continuous flow provides a positive pressure inside the mask to keep contaminates out and works on demand when the mask has a seal on the face.  The wide seal was important to us as we needed a mask that would accommodate beards, glasses and a variety of users. The speaking diaphragm has proven useful in communicating with the chamber operator.  Quick disconnect couplings have been installed in each chamber to provide medical air to the SAR. Each SAR in the chamber(s) has either 15 or 25 feet of air line hose.   For the personnel outside the chamber we chose the same masks with 100 feet of airline hose and the addition of a hip mounted air device.  The hip air device is a small 2000 psi bottle that will provide ten minutes of air.  These bottles come in various sizes.  For our facility and with the airlines we felt that ten minutes was adequate in case the operator needed to disconnect from the air line for some reason.  The medical air for the SAR’s and the patient devices is supplied from 12 ‘H’ type cylinders.  Consideration needs to be given to the number of patient(s) and staff devices, the type of devices (supply requirements) and the amount of time they would need to provide air supply in an emergency.  There have been some discussions about OSHA requirements such as fit testing, eye glasses, beards and special physicals to be able for staff to use the Survair masks.  We have answered these with the NFPA 99 requirements and special training for the staff.  We are not trying to maintain a certification to enter work in a hazardous environment. We are using the equipment to evacuate patients and staff from a hazardous environment.   The devices require regular maintenance and testing.  The apparatus and system are incorporated into fire drills and orientations to insure that all staff is familiar with the equipment and supply system.   The drills and maintenance of the mask need to be documented.

Key Operational Issues

  1. There must be individual breathing apparatus for all occupants of a class A chamber and a secure source of breathing gas for personnel outside the chamber.
  2. There must be a secure source of breathing gas for all personnel inside and outside of the chamber.

Bottom Line

Fatalities have occurred when a safe source of breathing gas was not available.  There are several types of apparatus available.  This equipment should be incorporated into your emergency drills so that all chamber staff knows how to use the apparatus and supply systems.

Reading Assignment

  1. NFPA 99 chapter 20, 20.2.4.1.3; 20.2.4.1.3.1; 20.2.4.3.2.2; 20.2.4.1.3.3; 20.2.4.1.3.4; 20.2.4.5.3; A.20.2.4.5.3
  2. Contact your local safety equipment supplier and / or search the web for Supplied Air Respirators and related equipment.

Contributing Author: James Bell, CHT, EMT

James Bell Jim has over 25 years experience in the operation and maintenance of multiplace hyperbaric chambers. He serves as safety director and lead hyperbaric technologist at Hennepin County Medical Center, in Minneapolis, Minnesota, USA. Jim is a certified hyperbaric technologist, and an Undersea and Hyperbaric Medical Society facility accreditation surveyor.

Full Panel of Safety and Technical Correspondents