Lithium Hydroxide Absorbent Name
The lithium hydroxide (LiOH) absorbent used as a CO₂ scrubber is commonly referred to as "lithium hydroxide" or "LiOH absorbent" in medical and life support applications, without a specific proprietary name in most contexts.
Chemical Composition and Forms
Lithium hydroxide serves as a standalone CO₂ absorbent in various life support systems, including closed-circuit rebreathers, submarine environments, and anesthesia circuits 1
The compound exists in granular form for use in scrubber canisters, where it chemically reacts with carbon dioxide to remove it from breathing circuits 2, 3
Performance Characteristics
Lithium hydroxide demonstrates the highest CO₂ absorption capacity among common absorbents, with optimal performance occurring at a residence time of approximately 0.8 seconds 3
The theoretical stoichiometric scrubbing capacity approaches 0.919 (mass of CO₂ scrubbed per unit mass of agent), with practical applications achieving capacities of 0.756-0.808 2
This absorbent produces dramatically lower concentrations of toxic byproducts (carbon monoxide and Compound A) compared to traditional soda lime absorbents containing potassium hydroxide or sodium hydroxide 1
Clinical Applications and Context
In submarine disabled survivor (DISSUB) scenarios, lithium hydroxide has traditionally been dispersed using the "stir-and-fan" method, though this releases caustic dust 2
Newer technologies like the Battelle Curtain and Micropore Reactive Plastic Curtain incorporate lithium hydroxide in formats that minimize dust exposure while maintaining near-stoichiometric scrubbing efficiency 2
In pediatric tracheostomy care, hygroscopic condenser humidifiers may contain lithium chloride (not hydroxide) as a hygroscopic chemical, though one study documented potential toxic absorption in small children 4
Important Safety Considerations
Lithium hydroxide is highly caustic and requires careful handling to prevent chemical burns 2
When used in granular form without protective barriers, trained personnel should use personal protective equipment due to the caustic nature of the dust 2
The compound's absorption capacity is influenced by environmental factors including residence time, porosity, and moisture content 3