ST53 Plus

  • ST53 Plus

The Avon ST53 Plus SCBA is a new product offering built from the revolutionary, field proven ST53™ multi-role Respiratory Equipment (RPE) system platform. It was developed specifically for specialist applications where the user needs to respond to ever changing operational conditions and incorporates the latest Avon fire hardened FM54 Air Purifying Respirator (APR).

The ST53 Plus SCBA combines the latest technological advancements of the FM54 APR providing Specialist Operators maximum level of protection to face, eyes and respiratory tract from Chemical, Biological, Radiological and Nuclear (CBRN), Riot Agents, Toxic Industrial Chemicals and Toxic Industrial Materials while maintaining extreme user flexibility as mission profiles change.

The ST53 Plus SCBA and new FM54 mask affords the user the ability to seamlessly switch from negative to positive pressure offering the operator with total flexibility to select the necessary level of protection quickly and efficiently while continuing to operate effectively.

ST53 Plus
ST53 Plus Datasheet

For further information please download the ST53 Plus Datasheet.


st53 features1

Compact Demand Valve (CDV)

  • 1st breath activated for "instant on"
  • Rugged, compact design delivers high flow rates
  • Screw-on-design allows for DIN 40 thread
st53 features2

Gauge & Whistle

  • Located on shoulder straps for easy access
  • Positioned for high noise environments and easy gauge reading
  • Illuminated gauge for low-light situations
st53 features3

Stealth Appearance 

  • Black low profile design
  • Lightweight compared to traditional SCBA units
  • Silent operation for critical missions
st53 features4


  • Ergonomically contoured backframe for comfort
  • Adjustable harness allows for quick donning/ doffing 
  • Padded shoulder straps for comfort

Technical Data

Breathing Performance in SCBA mode 
Breathing Rate  103 liters per minute with mask pressure above ambient
Environmental range  The operating range is -30oC + 60oC
End of cylinder air Able to sustain positive pressure down to 10 bar cylinder pressure
Breathing performance in ST PAPR Mode Breathing rate 125-165 liters per minute 
Breathing performance in APR mode
Breathing resistance  Exhalation breathing resistance of no greater than 20mm of water at 85 lpm in a negative pressure mode
Inhalation resistance including General Purpose Filter 50 mm of water at 85 lpm
Live agent permeation performance (Data validated by ECBC, Edgewood Chemical Biological Center)

  Requirements Actual Test agent  NIOSH CBRN Requirements Typical Performance 
Challenge Chemical  Max Peak (mg/m3) Max Cumulative (mg-min/m3) Max Peak (mg-m3) Max Cumulative  (mg-min/m)
Sarin (GB)  0.6  0.004 0.203  Mustard (HD)  6 Hours  > 6 Hours
Mustard (HD)  0.087 6  0.005 0.8   Sarin (GB)  6 Hours  > 6 Hours
Materials used
Harness on ST53 SCBA Kevlar webbing with stainless steel nylon hardware
Harness on ST53SD SCBA Nylon Cordura
Backplate  Glass reinforced polycarbonate
Cylinder valve Anodized Aluminum
ST-PAPR GE Noryl with a 10% glass fill
Weight for ST53 units (based on empty cylinders) Weight for ST53 Plus units (based on empty cylinders)
ST53 (excluding cylinder and mask) 6.6 lbs ST53SD 11 cu. ft (includes cylinder but no mask)

5.2 lbs

Carbon fiber fully wrapped, 2216 psi, 30 minute 7.75 lbs
Carbon fiber fully wrapped, 4500 psi, 30 minute 7.4 lbs
Carbon fiber fully wrapped, 4500 psi, 45 minute 9.9 lbs ST53SD 17 cu. ft (includes cylinder but no mask) 4.0 lbs
Carbon fiber fully wrapped, 4500 psi, 60 minute 11.95 lbs
Weight for ST-PAPR Weight for mask only 
ST-PAPR without CDV, battery or cartridges 2.5 lbs Single Port FM53 mask (excluding filter) 1.2 lbs
ST-PAPR without CDV, two general purpose filters and a lithium Sulphur Dioxide battery 4.4 lbs Dual Port FM53 mask (excluding filter) 1.3 lbs


  • Type-examination approval: PPE Regulation 2016/424/EU - Module B: Certificate CE 684849
  • The Avon ST53 Plus SCBA carries a NIOSH Industrial Approval under the provisions of 42 CFR 84 TC-13F in a variety of cylinder and facepiece size combinations.