Ocenco EBA 6.5 SCBA Air Time Calculator

The Ocenco EBA 6.5 is a closed-circuit oxygen rebreather certified by MSHA and NIOSH for mining self-rescue. It recycles exhaled breath through a CO2 scrubber and replenishes oxygen, providing 60 minutes of active escape or up to 8 hours in a barricade shelter scenario — far beyond what any open-circuit SCBA of similar size can provide.

Closed-circuit rebreather: how the EBA 6.5 achieves 60 minutes

The EBA 6.5 does not exhaust each breath to atmosphere — instead, exhaled air passes through a CO2 scrubber (chemical absorbent that removes carbon dioxide) and has oxygen replenished from the cylinder before being re-breathed. Total oxygen consumption per minute is approximately 0.3–0.5 L/min at rest and 1.0–3.5 L/min at working pace — far less than the 6–15 L/min oxygen demand of an open-circuit SCBA at the same breathing rates. This is why 1.8L at 200 bar = 360L of oxygen provides 60+ minutes when used in a rebreather.

60-minute escape vs 8-hour shelter: choosing the right mode

The MSHA 60-minute active escape rating assumes continuous movement at mining escape pace — physically demanding, sustained effort. If the mine collapse or gas event prevents escape movement and the miner must barricade in place (shelter in a sealed refuge area or barricade location), the EBA 6.5's reduced oxygen consumption (metabolism at rest) extends duration to 8 hours. Mining emergency plans should specify when escape vs barricade protocols apply — the EBA 6.5 supports both, but CO2 scrubber efficiency diminishes over time and temperature affects performance.

CO2 scrubber performance and temperature

The CO2 scrubber in the EBA 6.5 is a chemical absorbent (typically caustic lime or similar) that reacts with exhaled CO2. Scrubber performance is affected by temperature: very cold environments reduce reaction rate, potentially allowing CO2 breakthrough before the oxygen supply is exhausted. Very high temperatures can accelerate scrubber consumption. MSHA certification tests are conducted at standard temperature ranges — in extreme thermal environments, treat manufacturer duration ratings as conservative estimates and refer to Ocenco's technical documentation for temperature-specific performance data.

EBA 6.5 vs M-20.2: two different Ocenco products for different applications

The Ocenco M-20.2 is a small demand-flow EEBD for vessel/industrial emergency egress — 10 minutes, worn on a belt, designed for surface escapes. The EBA 6.5 is a large SCSR for mining escape or barricade survival — 60 minutes to 8 hours, worn over the shoulder. They share a brand and oxygen-based technology but serve entirely different environments. Do not substitute one for the other in planning or procurement.

FAQ

Ocenco EEBD & SCSR Duration Calculator – M-20.2 and EBA 6.5

Important: Ocenco devices are NOT conventional compressed-air SCBA. The M-20.2 is a belt-worn EEBD (Emergency Escape Breathing Device) using compressed oxygen, rated for escape from hazardous atmospheres — not entry or firefighting. The EBA 6.5 is a SCSR (Self-Contained Self-Rescuer), a closed-circuit rebreather using oxygen for extended mining escape. Standard SCBA air time formulas do not directly apply to oxygen-based or rebreather devices. The duration estimates on this page use modified inputs to approximate rated duration — always refer to manufacturer documentation for certified duration.

EEBD vs SCBA vs SCSR: critical distinctions

An SCBA (Self-Contained Breathing Apparatus, EN 137 / NFPA 1981) is certified for entry into IDLH atmospheres and structural firefighting. An EEBD (EN 1146 / NIOSH 42 CFR 84) is certified for emergency escape only — evacuating from a hazardous area to safety — not entry. An SCSR (MSHA/NIOSH for mining) is a closed-circuit rebreather for self-rescue in mining emergencies, typically with much longer rated duration due to oxygen-scrubbing chemistry. Using an EEBD or SCSR as a substitute for entry-certified SCBA is not permitted under any safety standard and creates serious risk.

Ocenco M-20.2: compressed oxygen EEBD — not compressed air

The Ocenco M-20.2 uses a compressed oxygen cylinder (0.4L at 200 bar), not compressed breathing air. This matters for calculation: standard SCBA formulas assume nitrogen-oxygen air mixture. With 100% oxygen, the demand valve flow rate, cylinder charge, and rated duration are calculated differently by the manufacturer. The M-20.2 is NIOSH-rated for 10 minutes at working level or up to 32 minutes at rest. The calculator inputs for this unit are configured to approximate this rated range — do not override with custom pressure inputs unless you have manufacturer documentation supporting different values.

Ocenco EBA 6.5: closed-circuit rebreather for mining escape

The EBA 6.5 is MSHA and NIOSH certified for mining self-rescue operations. It operates as a closed-circuit rebreather: exhaled breath passes through a CO2 scrubber, has oxygen replenished from the cylinder, and is re-breathed. This dramatically extends duration compared to open-circuit SCBA at the same cylinder size. The EBA 6.5 is rated for 60 minutes of active escape or up to 8 hours in a waiting/survival shelter scenario. The calculator uses approximate inputs; actual duration depends heavily on workload and CO2 scrubber performance.

Why standard RMV values don't apply to the M-20.2 and EBA 6.5

Standard firefighting RMV presets (30–75 L/min) reflect open-circuit air consumption rates. Closed-circuit devices (EBA 6.5) recycle exhaled gas, so total oxygen consumption per minute is far lower than equivalent open-circuit consumption. The M-20.2 (demand-flow oxygen) uses a different demand flow profile. RMV presets on these models are set to reflect effective oxygen depletion rates that approximate manufacturer-rated duration, not direct L/min breathing rates.

Where Ocenco devices are typically deployed

The M-20.2 EEBD is the world's smallest belt-worn escape device and is used extensively in vessel crew escape kits (SOLAS-regulated), industrial facility emergency egress, and confined space rescue support. The EBA 6.5 is primarily a mining emergency device for self-rescue from collapsed or gas-hazard environments. Neither is a firefighting tool — their value is in escape and survival, not entry and suppression.

FAQ

This is an estimate based on the values you enter. Real-world air consumption changes with workload, stress, temperature, mask seal, leaks, and individual physiology. Always follow your SOPs and monitor your pressure gauge continuously.