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Civil Defence Supply
Research, development, testing, manufacture, supply and training of specialised Defence and Law Enforcement products
SCBA Option - Most people associate SCBA systems with fire fighters and rescue. These are ‘pure’ SCBA systems with a close-cycle face-piece especially designed for a pressurised air supply. These are known as ‘Positive-Pressure’ masks as the incoming air is being forced into the face-piece through a demand valve and exits through a special valve that prevents straight flow-through. As the user breathes exactly the right volume of pressurised air is released into the face-piece, on demand.
The limiting factor with any SCBA System is the capacity of the air cylinder worn on the back. Various fill-pressures and cylinder sizes give long or short duration with the absolute maximum about 60 minutes from a large capacity high-pressure cylinder. Once reduced to nearly zero cylinder content a warning device sounds to advise the wearer to exit the hazardous area and find a replacement full cylinder.
In a non-fire-fighting operation having a strictly limited cylinder capacity is hazardous and very undesirable as rapid or frequent replacement is hard to plan for. Exertion increases air use dramatically making a theoretical 60mins actually 40mins or less.
SCBA Option - FRR
There are numerous designs of modern gas mask now available for police, firearms use and first responders however the FRR is entirely different as it was designed form the outset to accept an external air supply as a Self Contained Breathing Apparatus or SCBA.
A normal gas mask has a Negative-Pressure face-piece which means that the wearer has to physically inhale air through the filter system to breathe. Nothing drives that air into the mask apart from the users lungs at work. As the wearer exhales the air pathway is through an exit-valve back out to the atmosphere which rapidly shuts as the user breathes in again, preventing back-flow.
Normal gas masks give excellent protection against particulate materials, dusts, toxic chemicals, radiological debris and gases but in a low-oxygen or highly toxic environment or within a fire where not only oxygen is reduced but other toxic materials are present, the wearer of a standard gas mask is put at serious risk.
This is when a breathing apparatus with compressed air (SCBA) becomes a necessity.
Although the UK Ministry of Defence has adopted this new tear-drop shaped CBRN Canister civil agencies, the police and all other First responders still have substantial stocks of 40mm DIN-threaded CBRN canisters and it was logical to modify the MoD GSR facepiece to accept these civil canisters.