Lithium hydride LiH
LiH · CAS 7580-67-8
Lithium hydride (LiH) is a white-to-grey powder with a density of 0.78 g/cm3 at 20 °C and a melting point of 688 °C, according to the Albemarle technical data sheet.
Evidence level
2 of 5
Lab-measured
- 0Predicted only. No one has made it, or no measurement exists.
- 1Calculated. Only calculated or predicted values from sources.
- 2Lab-measured. Measured properties with their conditions stated.
- 3Space-relevant tests. Measured in conditions relevant to space, such as vacuum or atomic oxygen.
- 4Ground-qualified. Qualified for an application on the ground.
- 5Flown or field-proven. Flight or field results exist.
Density
0.78 g/cm³
Hydrogen content
12.7 %
Melting point
688 °C
Purity
97 %
Recipe, share of the weight
- Li 87.3%Lithium
- H 12.7%Hydrogen
Best for
Neutron shielding in space reactor designs where hydrogen per unit mass matters most (NASA TM X-1874 and the NASA nuclear thermal propulsion shielding paper)
Weakest at
Water and humid air: the powder hydrolyses rapidly and releases flammable gas, and NASA reports poor thermal conductivity, which makes active cooling of a LiH shield very difficult
Risk at a glance
- People None found. Corrosive, toxic powder that reacts with water
- If it fails High. Contact with water or humid air
- Corrosion Severe. Lithium hydride hydrolyses rapidly and decomposes in contact with humidity, so it must be kept sealed and dry.
Quick facts: LiH
| Property | Value | Basis |
|---|---|---|
| Density | 0.78 g/cm³ | 1 sourced value |
| Melting point | 688 °C | 1 sourced value |
What is the density of Lithium hydride (LiH)?
Lithium hydride (LiH) has a density of 0.78 g/cm³. The source and test conditions are listed in the properties table on this page.
What is the melting point of Lithium hydride (LiH)?
Lithium hydride (LiH) has a melting point of 688 °C. The source and test conditions are listed in the properties table on this page.
What is Lithium hydride (LiH) used for?
Uses recorded in the sources include Layered shield for a nuclear space power reactor (NASA TM X-1874 study, ground analysis); Neutron shield in nuclear thermal propulsion designs (NASA MSFC shielding study); Industrial reducing agent and high-density hydrogen source (terrestrial chemistry, not a flight application).
Why it exists
Lithium hydride (LiH) is a lithium compound with a high hydrogen content. Albemarle's technical data sheet gives a density of 0.78 g/cm3 and a melting point of 688 °C, and says that the powder decomposes in contact with humidity. NASA's 1969 shield study found LiH to be one of the best neutron shield materials for a space power reactor. A later NASA paper calls it the most effective neutron shield per unit mass, but it sets LiH aside because a simple cooling model could not keep the shield within temperature limits.
Where it's used
Space reactor radiation shields
NASA's 1969 ground study of a 2.2 MW-thermal fast-spectrum reactor found an optimized shield weight of 25 300 kg with depleted uranium and 28 500 kg with tungsten. Both designs used natural lithium hydride as the neutron shield, in four layers alternated with three metal layers.
Nuclear thermal propulsion shielding
A later NASA shielding paper says lithium hydride is the most effective neutron shield per unit mass, but its poor thermal conductivity makes cooling nearly impossible in a high-flux reactor. The study chose a boron carbide pebble bed instead.
Chemistry
Albemarle sells lithium hydride as a reducing agent, a high-density hydrogen source and a raw material for high-purity monosilanes. These are terrestrial industrial uses, not space applications.
Recipe
LiH
LiH is lithium hydride: one lithium atom and one hydrogen atom per formula unit, as printed in the Albemarle molecular formula. The natural lithium used in NASA's shield model is a mix of lithium-6 and lithium-7.
| Ingredient | Atoms per unit | Share of the weight | What it does |
|---|---|---|---|
| Lithium Li | 1 | 87.3% | The neutron absorber. NASA says lithium-6 has a dominant (n,alpha) reaction and that LiH is an excellent neutron absorber when enriched in Li-6; the NASA model uses natural lithium. The atomic weight is the lower bound of the CIAAW interval [6.938, 6.997]. |
| Hydrogen H | 1 | 12.7% | The moderator. NASA says hydrogen sheds fast-neutron energy by collisions with light atoms, and LiH has a high hydrogen density. The atomic weight is the lower bound of the CIAAW interval [1.00784, 1.00811]. |
Weight shares are calculated from standard atomic weights.
What it can do
Density
0.78 g/cm³
measured
Lithium hydride powder has a density of 0.78 g/cm3 at 20 °C, per the Albemarle data sheet. Its bulk density is 290 to 400 kg/m3 as a powder.
Hydrogen content
12.7 %
worked out from the formula
The theoretical hydrogen content is 12.7 %, and the data sheet gives 2.82 litres of hydrogen evolved per gram of LiH in hydrolysis. This is the figure behind its use as a high-density hydrogen source.
Melting point
688 °C
measured
The data sheet gives a melting point of 688 °C and a thermal decomposition at about 800 °C.
Purity
97 %
measured
The supplier specification is a minimum of 97 % LiH, with sodium at most 0.9 % and potassium at most 0.05 %.
How it compares
Lithium hydride is the most effective neutron shield per unit mass in NASA's reactor-shield studies, but its cooling is difficult. The NASA shielding paper by Caffrey and colleagues says a boron carbide shield has a mass penalty of about 20 % greater than a practical LiH shield, and that boron carbide has excellent thermal conductivity, hardness and chemical stability. The table compares LiH with the reference points in this profile.
The same measurements for each material, so you can compare them. Each row names the key condition under the value; the full conditions and methods are in the numbered notes under Technical details. Compare every grade in the family.
| Measurement | LiH |
|---|---|
| Thermal behavior and safety | |
| Melting point, LiH powder | 688 °C2 |
| Thermal decomposition temperature of LiH | 800 °C4 |
| Physical and electrical | |
| Density, LiH powder, 20 °C | 0.78 g/cm³1 |
| Bulk density, LiH powder | 290 to 400 kg/m311 |
| Hydrogen atom density, natural LiH in a reactor shield model | 0.05684 atoms/barn-cm12 |
| Lithium-6 atom density, natural LiH in a reactor shield model | 0.004217 atoms/barn-cm13 |
| Lithium-7 atom density, natural LiH in a reactor shield model | 0.05262 atoms/barn-cm14 |
| Other measurements | |
| Molar mass of LiH | 7.95 g/mol3 |
| Theoretical hydrogen content of LiH | 12.7 %5 |
| Hydrogen evolved per gram of LiH in hydrolysis | 2.82 L/g6 |
| Hydrogen equilibrium pressure of LiH at 500 °C | 0.09 mbar7 |
| Hydrogen equilibrium pressure of LiH at 850 °C | 1010 mbar8 |
| LiH content, minimum (supplier specification) | 97 %9 |
| Sodium content, maximum (supplier specification) | 0.9 %10 |
Why choose it, and why not
Good for
- Neutron shielding by mass. NASA's studies call LiH the most effective neutron shield per unit mass (NASA shielding paper).
- Hydrogen-dense powder. The theoretical hydrogen content is 12.7 %, and Albemarle sells the powder as a high-density hydrogen source.
Watch out for
- Water and humid air. The powder hydrolyses rapidly and releases flammable gas (H260).
- Poor thermal conductivity. NASA says LiH is hard to cool in a high-flux reactor shield.
- Corrosive and toxic if swallowed. ICSC 0813 and PubChem describe the powder as corrosive (H314) and toxic (H301).
Lithium hydride is the hydrogen-rich neutron shield that NASA's studies rate highest per unit mass, but it must be kept dry and sealed, and it is hard to cool in a reactor. Its use in space shielding has been studied on paper and in ground analysis, and no flight result was found.
Technical details
For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | Density, LiH powder, 20 °C | Density printed in the Albemarle technical data sheet | temperature 20 °Cform powder, product 10000103 (< 100 µm) | — |
| 2 | Melting point, LiH powder | Melting point or range printed in the Albemarle technical data sheet (single value, no range given) | form powder, product 10000103 (< 100 µm)atmosphere not stated on the data sheet | — |
| 3 | Molar mass of LiH | Molecular weight printed in the Albemarle technical data sheet (page 2) | basis molecular weight as printed by the supplier | — |
| 4 | Thermal decomposition temperature of LiH | Thermal stability value printed in the Albemarle technical data sheet, given as an approximate figure | printed abt. 800 °Catmosphere not stated on the data sheet | — |
| 5 | Theoretical hydrogen content of LiH | Value printed in the Albemarle technical data sheet (Additional Physical Properties) | basis theoretical, from the formula LiH | — |
| 6 | Hydrogen evolved per gram of LiH in hydrolysis | Value printed in the Albemarle technical data sheet (Additional Physical Properties); the supplier does not give the gas temperature or pressure | basis hydrogen evolved in hydrolysis, as printed in litres of hydrogen per greaction reaction with water or moisture | — |
| 7 | Hydrogen equilibrium pressure of LiH at 500 °C | Equilibrium pressure printed in the Albemarle technical data sheet | temperature 500 °C | — |
| 8 | Hydrogen equilibrium pressure of LiH at 850 °C | Equilibrium pressure printed in the Albemarle technical data sheet as approximately 1,010 mbar | temperature 850 °C | — |
| 9 | LiH content, minimum (supplier specification) | Minimum specification printed in the Albemarle technical data sheet | grade product 10000103, powder < 100 µm | — |
| 10 | Sodium content, maximum (supplier specification) | Maximum specification printed in the Albemarle technical data sheet (upper bound) | grade product 10000103, powder < 100 µm | — |
| 11 | Bulk density, LiH powder | Range printed in the Albemarle technical data sheet | form powder, product 10000103 (< 100 µm) | — |
| 12 | Hydrogen atom density, natural LiH in a reactor shield model | Atom density printed in NASA TM X-1874 for the model; a calculation input, not a measured property | composition natural lithium hydride as modelled in the shield region of a 2.2 MWt fast-spectrum space reactorsource table Table I | — |
| 13 | Lithium-6 atom density, natural LiH in a reactor shield model | Atom density printed in NASA TM X-1874 for the model; a calculation input, not a measured property | composition natural lithium hydride as modelled in the shield region of a 2.2 MWt fast-spectrum space reactorsource table Table I | — |
| 14 | Lithium-7 atom density, natural LiH in a reactor shield model | Atom density printed in NASA TM X-1874 for the model; a calculation input, not a measured property | composition natural lithium hydride as modelled in the shield region of a 2.2 MWt fast-spectrum space reactorsource table Table I | — |
Corrosion and compatibility
What happens when it meets other materials and environments.
| Environment | Concern | What happens |
|---|---|---|
| Water and humid air | severe | Lithium hydride hydrolyses rapidly and decomposes in contact with humidity, so it must be kept sealed and dry.1 |
| Light and air at room conditions | moderate | The solid darkens on exposure to light and is hygroscopic.2 |
| Molten LiH in a reactor shield | moderate | Liquid LiH expands in volume, so containment must allow for it.3 |
| # | Environment | Details | Test conditions |
|---|---|---|---|
| 1 | Water and humid air | The Albemarle data sheet gives water solubility as 'Substance hydrolyses rapidly' and says the material decomposes in contact with humidity. ICSC 0813 says it reacts violently with water, producing corrosive lithium hydroxide fumes. The NASA shield paper says LiH is reactive and must be sealed within containment. | exposure contact with water or moist air, at room temperatureproduct LiH powder, product 10000103 |
| 2 | Light and air at room conditions | ICSC 0813 describes lithium hydride as an odourless white-to-greyish hygroscopic solid that darkens with light exposure. The Albemarle data sheet says that stored under exclusion of air and humidity the material is fairly stable and should be retested 6 months after the date of analysis. | exposure light and ambient air; exposure time not stated |
| 3 | Molten LiH in a reactor shield | NASA's shielding paper (Caffrey et al.) notes that the large volume expansion of lithium hydride in its melted liquid phase must be accounted for during casting and after containment closure, and that poor thermal conductivity limits cooling of the shield. | state melted liquid phase; expansion figure not given in the paper |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
The supplier and ICSC 0813 describe the powder as corrosive and toxic if swallowed, and it releases flammable gas on contact with water.
- The powder
- PubChem's GHS summary lists H314 (severe skin burns and eye damage, 100% of notifications), H301 (toxic if swallowed, 82.4%) and the signal word Danger.
- Dust and air
- ICSC 0813 says the solid is corrosive to the eyes, skin and respiratory tract, and inhalation may cause severe swelling of the throat. The TLV is 0.05 mg/m3 as a ceiling value.
- Water
- H260 (flammable gas released on contact with water, which may ignite spontaneously) is the main hazard that handlers must avoid.
If the material gets wet or overheats
These effects are from supplier and ICSC data, and from NASA design studies, not from incidents.
- Moisture
- The Albemarle data sheet says the material decomposes in contact with humidity and hydrolyses rapidly. Hydrogen is released.
- Heat
- The data sheet gives a thermal decomposition at about 800 °C and a hydrogen equilibrium pressure of 0.09 mbar at 500 °C, rising to about 1,010 mbar at 850 °C.
Handling and storage
- Atmosphere
- Albemarle says to handle the powder under an inert gas atmosphere and to store it in tightly closed containers, excluded from humidity.
- Transport
- UN 1414, class 4.3, packing group I, as printed by Albemarle for road, rail, sea and air transport.
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Contact with water or humid airhigh severity | Water or moisture reaching the powder or a containment that has been openedRapid hydrolysis releases flammable gas that may ignite spontaneously (GHS H260) and forms corrosive lithium hydroxide (ICSC 0813). |
| Dust-air mixturehigh severity | Handling or use of the powderIn use the powder may form flammable or explosive dust-air mixtures. |
| Heating above the stable rangemoderate severity | Heating of LiHThe Albemarle data sheet gives a thermal decomposition at about 800 °C and a hydrogen equilibrium pressure of 0.09 mbar at 500 °C rising to about 1,010 mbar at 850 °C, so hydrogen is released on heating. |
Side effects on surrounding parts
| Affects | Effect |
|---|---|
| Reactor shield cooling and temperature margins | NASA's shielding paper (Caffrey et al.) says LiH's poor thermal conductivity and narrow operating temperature range make effective cooling strategies nearly impossible in high-flux environments, which led the study to set LiH aside in favour of a boron carbide pebble bed. |
Handling and storage
- Albemarle: handle under an inert gas atmosphere, avoid contact with eyes, skin and clothing, and avoid inhalation. Store in tightly closed containers under exclusion of humidity at gentle temperatures, away from heat, sparks and fire.
- ICSC 0813: keep under mineral oil or inert gas, dry and cool, and separate from incompatible materials; store in an area without drain or sewer access.
- Transport: UN 1414, class 4.3, packing group I (ADR, RID, IMDG and IATA as printed by Albemarle).
Mitigations
- Retest the material 6 months after the date of analysis if the certificate of analysis is included, or use the manufacturing date for the calculation if it is not (Albemarle).
- NASA says the reactive nature of LiH mandates that it be sealed within some containment, and NASA's shield designs alternate LiH layers with metal layers to limit secondary gamma production.
Supply and geography
How common the raw materials are and where they come from.
Lithium
- Top producers (2025)
- Australia 31.7%, China 21.4%, Chile 19.3%, Zimbabwe 9.7%, Argentina 7.9%
- Recycling
- USGS: construction of lithium battery recycling plants continued throughout 2025, and automobile companies and battery recyclers partnered to supply battery materials.
- Substitutes
- USGS: substitution for lithium compounds is possible in batteries, ceramics, greases and manufactured glass.
Documents
Datasheets, safety data sheets, papers and standards you can open.
Full record
The complete spore, as stored. Free to reuse under CC-BY-4.0. Images keep the licence shown with each one.
Show the full YAML
spore: profile
id: lithium-hydride
spore_version: 0.2
family: lithium
name: Lithium hydride
abbreviation: LiH
role: neutron shield, hydrogen source and reducing agent
category: shielding
type: hydrogen-rich-polymers
summary: |
Lithium hydride (LiH) is a white-to-grey powder with a density of 0.78 g/cm3 at 20 °C and a melting point of 688 °C, according to the Albemarle technical data sheet. Its theoretical hydrogen content is 12.7 %. NASA's 1969 shield study calls lithium hydride one of the best neutron shield materials for a space power reactor, and a later NASA paper calls it the most effective neutron shield per unit mass. It hydrolyses rapidly in water and decomposes in humid air, so it must be kept dry and sealed.
best_for: Neutron shielding in space reactor designs where hydrogen per unit mass matters most (NASA TM X-1874 and the NASA nuclear thermal propulsion shielding paper)
weakest_at: 'Water and humid air: the powder hydrolyses rapidly and releases flammable gas, and NASA reports poor thermal conductivity, which makes active cooling of a LiH shield very difficult'
identity:
formula: LiH
cas: 7580-67-8
source: albemarle-tds
where: Title block (CAS-No. 7580-67-8; Molecular formula LiH); the product is Lithium Hydride, powder < 100 µm
tags:
environments: []
stresses:
- total-radiation-dose
applications:
- radiation-shielding
- electronics-and-chips
properties:
- benchmark: density
label: Density, LiH powder, 20 °C
value: 0.78
unit: g/cm3
scope: material
conditions:
temperature: 20 °C
form: powder, product 10000103 (< 100 µm)
method: Density printed in the Albemarle technical data sheet
status: ground
source: albemarle-tds
where: Physical properties, Density row
- benchmark: melting_point
label: Melting point, LiH powder
value: 688
unit: °C
scope: material
conditions:
form: powder, product 10000103 (< 100 µm)
atmosphere: not stated on the data sheet
method: Melting point or range printed in the Albemarle technical data sheet (single value, no range given)
status: ground
source: albemarle-tds
where: Physical properties, Melting point/range row
- benchmark: molar_mass
label: Molar mass of LiH
value: 7.95
unit: g/mol
scope: material
conditions:
basis: molecular weight as printed by the supplier
method: Molecular weight printed in the Albemarle technical data sheet (page 2)
status: ground
source: albemarle-tds
where: Page 2, Molecular weight row
- benchmark: thermal_decomposition_temperature
label: Thermal decomposition temperature of LiH
value: 800
unit: °C
scope: material
conditions:
printed: abt. 800 °C
atmosphere: not stated on the data sheet
method: Thermal stability value printed in the Albemarle technical data sheet, given as an approximate figure
status: ground
source: albemarle-tds
where: Page 2, Thermal Stability row
- benchmark: theoretical_hydrogen_content
label: Theoretical hydrogen content of LiH
value: 12.7
unit: '%'
scope: material
conditions:
basis: theoretical, from the formula LiH
method: Value printed in the Albemarle technical data sheet (Additional Physical Properties)
status: calculated
source: albemarle-tds
where: Page 2, Additional Physical Properties row
- benchmark: hydrogen_yield_from_hydrolysis
label: Hydrogen evolved per gram of LiH in hydrolysis
value: 2.82
unit: L/g
scope: material
conditions:
basis: hydrogen evolved in hydrolysis, as printed in litres of hydrogen per g
reaction: reaction with water or moisture
method: Value printed in the Albemarle technical data sheet (Additional Physical Properties); the supplier does not give the gas temperature or pressure
status: calculated
source: albemarle-tds
where: Page 2, Additional Physical Properties row
- benchmark: hydrogen_equilibrium_pressure
label: Hydrogen equilibrium pressure of LiH at 500 °C
value: 0.09
unit: mbar
scope: material
conditions:
temperature: 500 °C
method: Equilibrium pressure printed in the Albemarle technical data sheet
status: ground
source: albemarle-tds
where: Page 2, Additional Physical Properties row
- benchmark: hydrogen_equilibrium_pressure
label: Hydrogen equilibrium pressure of LiH at 850 °C
value: 1010
unit: mbar
scope: material
conditions:
temperature: 850 °C
method: Equilibrium pressure printed in the Albemarle technical data sheet as approximately 1,010 mbar
status: ground
source: albemarle-tds
where: Page 2, Additional Physical Properties row
- benchmark: assay
label: LiH content, minimum (supplier specification)
value: 97
unit: '%'
scope: material
conditions:
grade: product 10000103, powder < 100 µm
method: Minimum specification printed in the Albemarle technical data sheet
status: ground
source: albemarle-tds
where: Specification table, LiH row
- benchmark: impurity_sodium
label: Sodium content, maximum (supplier specification)
value: 0.9
unit: '%'
scope: material
conditions:
grade: product 10000103, powder < 100 µm
method: Maximum specification printed in the Albemarle technical data sheet (upper bound)
status: ground
source: albemarle-tds
where: Specification table, Na row
- benchmark: bulk_density
label: Bulk density, LiH powder
value: 290
value_high: 400
bound: range
unit: kg/m3
scope: material
conditions:
form: powder, product 10000103 (< 100 µm)
method: Range printed in the Albemarle technical data sheet
status: ground
source: albemarle-tds
where: Physical properties, Bulk density row
- benchmark: hydrogen_atom_density
label: Hydrogen atom density, natural LiH in a reactor shield model
value: 0.056837
unit: atoms/barn-cm
scope: material
conditions:
composition: natural lithium hydride as modelled in the shield region of a 2.2 MWt fast-spectrum space reactor
source_table: Table I
method: Atom density printed in NASA TM X-1874 for the model; a calculation input, not a measured property
status: ground
source: nasa-tmx1874
where: Table I, Shield, natural lithium hydride, Hydrogen row
- benchmark: lithium_6_atom_density
label: Lithium-6 atom density, natural LiH in a reactor shield model
value: 0.004217
unit: atoms/barn-cm
scope: material
conditions:
composition: natural lithium hydride as modelled in the shield region of a 2.2 MWt fast-spectrum space reactor
source_table: Table I
method: Atom density printed in NASA TM X-1874 for the model; a calculation input, not a measured property
status: ground
source: nasa-tmx1874
where: Table I, Shield, natural lithium hydride, Lithium-6 row
- benchmark: lithium_7_atom_density
label: Lithium-7 atom density, natural LiH in a reactor shield model
value: 0.05262
unit: atoms/barn-cm
scope: material
conditions:
composition: natural lithium hydride as modelled in the shield region of a 2.2 MWt fast-spectrum space reactor
source_table: Table I
method: Atom density printed in NASA TM X-1874 for the model; a calculation input, not a measured property
status: ground
source: nasa-tmx1874
where: Table I, Shield, natural lithium hydride, Lithium-7 row
corrosion:
- environment: Water and humid air
headline: Lithium hydride hydrolyses rapidly and decomposes in contact with humidity, so it must be kept sealed and dry.
effect: The Albemarle data sheet gives water solubility as 'Substance hydrolyses rapidly' and says the material decomposes in contact with humidity. ICSC 0813 says it reacts violently with water, producing corrosive lithium hydroxide fumes. The NASA shield paper says LiH is reactive and must be sealed within containment.
rating: severe
conditions:
exposure: contact with water or moist air, at room temperature
product: LiH powder, product 10000103
source: albemarle-tds
where: Page 2, Water solubility row; Handling and Storage
- environment: Light and air at room conditions
headline: The solid darkens on exposure to light and is hygroscopic.
effect: ICSC 0813 describes lithium hydride as an odourless white-to-greyish hygroscopic solid that darkens with light exposure. The Albemarle data sheet says that stored under exclusion of air and humidity the material is fairly stable and should be retested 6 months after the date of analysis.
rating: moderate
conditions:
exposure: light and ambient air; exposure time not stated
source: icsc-0813
where: Physical State; Appearance
- environment: Molten LiH in a reactor shield
headline: Liquid LiH expands in volume, so containment must allow for it.
effect: NASA's shielding paper (Caffrey et al.) notes that the large volume expansion of lithium hydride in its melted liquid phase must be accounted for during casting and after containment closure, and that poor thermal conductivity limits cooling of the shield.
rating: moderate
conditions:
state: melted liquid phase; expansion figure not given in the paper
source: caffrey-ntp
where: Material Selection section
risks:
hazards:
- text: PubChem's GHS summary for lithium hydride (CID 62714) lists the signal word Danger and hazard statement H260 (in contact with water releases flammable gases which may ignite spontaneously, 99.5% of ECHA notifications), H301 (toxic if swallowed, 82.4%) and H314 (causes severe skin burns and eye damage, 100%).
ghs: []
source: pubchem-lih
where: GHS Classification, ECHA notified classification ratios
- text: ICSC 0813 describes the substance as corrosive to the eyes, skin and respiratory tract; inhalation may cause severe swelling of the throat. The card gives a TLV of 0.05 mg/m3 (ceiling value) and an EU-OEL of 0.02 mg/m3 as STEL, both for the inhalable fraction.
ghs: []
source: icsc-0813
where: Health Hazards and First Aid; Occupational Exposure Limits
failure_risks:
- mode: Contact with water or humid air
trigger: Water or moisture reaching the powder or a containment that has been opened
consequence: Rapid hydrolysis releases flammable gas that may ignite spontaneously (GHS H260) and forms corrosive lithium hydroxide (ICSC 0813).
severity: high
source: icsc-0813
where: Chemical Dangers; GHS hazard statement H260
- mode: Dust-air mixture
trigger: Handling or use of the powder
consequence: In use the powder may form flammable or explosive dust-air mixtures.
severity: high
source: albemarle-tds
where: Page 2, Handling
- mode: Heating above the stable range
trigger: Heating of LiH
consequence: The Albemarle data sheet gives a thermal decomposition at about 800 °C and a hydrogen equilibrium pressure of 0.09 mbar at 500 °C rising to about 1,010 mbar at 850 °C, so hydrogen is released on heating.
severity: moderate
source: albemarle-tds
where: Page 2, Thermal Stability and Additional Physical Properties rows
side_effects:
- text: NASA's shielding paper (Caffrey et al.) says LiH's poor thermal conductivity and narrow operating temperature range make effective cooling strategies nearly impossible in high-flux environments, which led the study to set LiH aside in favour of a boron carbide pebble bed.
affects: Reactor shield cooling and temperature margins
source: caffrey-ntp
where: Material Selection section; Shielding Development section on heating
handling:
- text: 'Albemarle: handle under an inert gas atmosphere, avoid contact with eyes, skin and clothing, and avoid inhalation. Store in tightly closed containers under exclusion of humidity at gentle temperatures, away from heat, sparks and fire.'
source: albemarle-tds
where: Handling & Storage
- text: 'ICSC 0813: keep under mineral oil or inert gas, dry and cool, and separate from incompatible materials; store in an area without drain or sewer access.'
source: icsc-0813
where: Storage
- text: 'Transport: UN 1414, class 4.3, packing group I (ADR, RID, IMDG and IATA as printed by Albemarle).'
source: albemarle-tds
where: Transport & Packaging
mitigations:
- text: Retest the material 6 months after the date of analysis if the certificate of analysis is included, or use the manufacturing date for the calculation if it is not (Albemarle).
source: albemarle-tds
where: Handling & Storage
- text: NASA says the reactive nature of LiH mandates that it be sealed within some containment, and NASA's shield designs alternate LiH layers with metal layers to limit secondary gamma production.
source: caffrey-ntp
where: Material Selection section
uses:
- application: radiation-shielding
device: Layered shield for a nuclear space power reactor (NASA TM X-1874 study, ground analysis)
example: NASA's 1969 study found an optimized shield weight of 25 300 kg with depleted uranium and 28 500 kg with tungsten, for a 2.2 MW-thermal fast-spectrum reactor, both using natural lithium hydride alternated with four metal layers as the neutron shield.
source: nasa-tmx1874
where: Abstract; Summary of results, paragraph on the optimized shield weights
- application: radiation-shielding
device: Neutron shield in nuclear thermal propulsion designs (NASA MSFC shielding study)
example: NASA's shielding paper calls LiH the most effective neutron shield per unit mass, owing to its hydrogen and to lithium-6, but the study set LiH aside in favour of a boron carbide pebble-bed shield for cooling reasons.
source: caffrey-ntp
where: Material Selection section; Shielding Development section on heating
- application: electronics-and-chips
device: Industrial reducing agent and high-density hydrogen source (terrestrial chemistry, not a flight application)
example: Albemarle lists lithium hydride as a reducing agent, a high-density hydrogen source and a material for producing high-purity monosilanes.
source: albemarle-tds
where: Application row, first page
supply:
- subject: Lithium
producers:
- country: Australia
share_percent: 31.7
year: 2025
- country: China
share_percent: 21.4
year: 2025
- country: Chile
share_percent: 19.3
year: 2025
- country: Zimbabwe
share_percent: 9.7
year: 2025
- country: Argentina
share_percent: 7.9
year: 2025
recycling: 'USGS: construction of lithium battery recycling plants continued throughout 2025, and automobile companies and battery recyclers partnered to supply battery materials.'
substitutes:
- 'USGS: substitution for lithium compounds is possible in batteries, ceramics, greases and manufactured glass.'
source: usgs-mcs2026-lithium
where: World Mine Production and Reserves table, 2025 (shares calculated by Space Mushroom against the 290,000 t world total in that table); Recycling; Substitutes
documents:
- title: 'Albemarle technical data sheet: Lithium Hydride, powder < 100 µm (product 10000103, issued 2025/11/28)'
type: datasheet
url: https://www.albemarle.com/sites/default/files/2026-01/_TDS_00000138_TDS_ALB_E.PDF
year: 2025
- title: 'NASA TM X-1874: Comparison of Tungsten and Depleted Uranium in Minimum-Weight, Layered Shields for a Space Power Reactor (1969)'
type: report
url: https://ntrs.nasa.gov/api/citations/19690026439/downloads/19690026439.pdf
year: 1969
- title: Shielding Development for Nuclear Thermal Propulsion (Caffrey, Gomez, Scharber; Oregon State University and NASA Marshall)
type: paper
url: https://ntrs.nasa.gov/api/citations/20150006884/downloads/20150006884.pdf
- title: 'PubChem: Lithium hydride (CID 62714), GHS classification summary'
type: database
url: https://pubchem.ncbi.nlm.nih.gov/compound/62714
year: 2026
- title: 'ICSC 0813: Lithium hydride (International Chemical Safety Card)'
type: database
url: https://www.inchem.org/documents/icsc/icsc/eics0813.htm
- title: 'USGS Mineral Commodity Summaries 2026: Lithium'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-lithium.pdf
year: 2026
- title: IUPAC CIAAW standard atomic weight of lithium
type: database
url: https://ciaaw.org/lithium.htm
year: 2009
- title: IUPAC CIAAW standard atomic weight of hydrogen
type: database
url: https://ciaaw.org/hydrogen.htm
year: 2009
gaps:
- No media (images or crystal-structure drawings) were added; no licensed image was checked in this run.
- No thermal conductivity or specific heat for LiH was found in a page we could read. Yaws' Handbook of Thermal Conductivity is the likely source but was not opened.
- No lattice constant or crystal system was taken from a fetched primary source; Wikipedia gives an fcc NaCl-type structure but is not used for numbers here.
- No boiling point, flash point or autoignition temperature was taken from a source we could open. Wikipedia lists values, but it is not used for numbers in this profile.
- Sigma-Aldrich safety data sheet (product 323403) timed out and was not read; hazard data rest on PubChem, ICSC 0813 and the Albemarle data sheet.
- Manufacturing route and purity controls beyond the Albemarle minimum assay and sodium and potassium limits were not found in a source we could read.
- Lithium abundance in the Earth's crust, and the USGS and EU critical-mineral list status for lithium, were not read in this run (the USGS 2026 lithium summary was read only for production shares and recycling and substitutes).
- Hydrogen supply and production shares were not read in a fetched source; the supply block covers lithium only.
- Molar mass, bulk density, thermal decomposition temperature and hydrogen equilibrium pressure are not canonical names in spores/property-canon.yaml; they are short snake_case or canonical-alias names and were not mapped to the canon file.
- Atomic weights for the recipe are the lower bounds of the CIAAW intervals (lithium [6.938, 6.997] and hydrogen [1.00784, 1.00811]); the single standard value is not printed by CIAAW.
- Space flight, vacuum and radiation-exposure results for LiH were not found in a source we could open; the NASA shield results are ground design analyses.
sources:
albemarle-tds:
title: 'Technical Data Sheet: Lithium Hydride, powder < 100 µm (Albemarle, product 10000103)'
id: Albemarle TDS, date of issue 2025/11/28; CAS 7580-67-8; EC 231-484-3
url: https://www.albemarle.com/sites/default/files/2026-01/_TDS_00000138_TDS_ALB_E.PDF
year: 2025
kind: datasheet
license: supplier document, linked not reproduced
nasa-tmx1874:
title: Comparison of Tungsten and Depleted Uranium in Minimum-Weight, Layered Shields for a Space Power Reactor (NASA TM X-1874, Lahti and Herrmann)
id: NASA NTRS 19690026439; NASA TM X-1874 (August 1969)
url: https://ntrs.nasa.gov/api/citations/19690026439/downloads/19690026439.pdf
year: 1969
kind: report
license: public domain (NASA)
caffrey-ntp:
title: Shielding Development for Nuclear Thermal Propulsion (Caffrey, Gomez, Scharber)
id: NASA NTRS 20150006884
url: https://ntrs.nasa.gov/api/citations/20150006884/downloads/20150006884.pdf
kind: paper
license: public domain (NASA)
icsc-0813:
title: 'ICSC 0813: Lithium hydride, International Programme on Chemical Safety'
id: ICSC 0813
url: https://www.inchem.org/documents/icsc/icsc/eics0813.htm
kind: handbook
license: public domain (IPCS/INCHEM)
pubchem-lih:
title: PubChem compound record, Lithium hydride (CID 62714)
id: CID 62714; EC 231-484-3
url: https://pubchem.ncbi.nlm.nih.gov/compound/62714
year: 2026
kind: database
license: public domain (NCBI)
usgs-mcs2026-lithium:
title: 'Mineral Commodity Summaries 2026: Lithium'
id: USGS MCS 2026, February 2026
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-lithium.pdf
year: 2026
kind: report
license: public domain (USGS)
ciaaw-lithium:
title: IUPAC CIAAW standard atomic weight of lithium
id: CIAAW, interval [6.938, 6.997], since 2009
url: https://ciaaw.org/lithium.htm
year: 2009
kind: database
license: CIAAW web page
ciaaw-hydrogen:
title: IUPAC CIAAW standard atomic weight of hydrogen
id: CIAAW, interval [1.00784, 1.00811], since 2009
url: https://ciaaw.org/hydrogen.htm
year: 2009
kind: database
license: CIAAW web page
license: CC-BY-4.0
updated: '2026-11-01'
review:
status: draft
method: assistant
checked_values: 14
unreachable: 1
caveats: 3
note: 'Written by an AI assistant on 2026-11-01 from pages read in this run: 14 property rows from the Albemarle datasheet and the NASA TM X-1874 atom-density table. The Sigma-Aldrich SDS timed out and was not read.'
story:
recipe:
line: 'LiH is lithium hydride: one lithium atom and one hydrogen atom per formula unit, as printed in the Albemarle molecular formula. The natural lithium used in NASA''s shield model is a mix of lithium-6 and lithium-7.'
parts:
- name: Lithium
symbol: Li
atoms: 1
atomic_weight: 6.938
role: The neutron absorber. NASA says lithium-6 has a dominant (n,alpha) reaction and that LiH is an excellent neutron absorber when enriched in Li-6; the NASA model uses natural lithium. The atomic weight is the lower bound of the CIAAW interval [6.938, 6.997].
- name: Hydrogen
symbol: H
atoms: 1
atomic_weight: 1.00784
role: The moderator. NASA says hydrogen sheds fast-neutron energy by collisions with light atoms, and LiH has a high hydrogen density. The atomic weight is the lower bound of the CIAAW interval [1.00784, 1.00811].
risk_groups:
- title: For people
level: 0
verdict: Corrosive, toxic powder that reacts with water
lead: The supplier and ICSC 0813 describe the powder as corrosive and toxic if swallowed, and it releases flammable gas on contact with water.
points:
- label: The powder
line: PubChem's GHS summary lists H314 (severe skin burns and eye damage, 100% of notifications), H301 (toxic if swallowed, 82.4%) and the signal word Danger.
- label: Dust and air
line: ICSC 0813 says the solid is corrosive to the eyes, skin and respiratory tract, and inhalation may cause severe swelling of the throat. The TLV is 0.05 mg/m3 as a ceiling value.
- label: Water
line: H260 (flammable gas released on contact with water, which may ignite spontaneously) is the main hazard that handlers must avoid.
- title: If the material gets wet or overheats
lead: These effects are from supplier and ICSC data, and from NASA design studies, not from incidents.
points:
- label: Moisture
line: The Albemarle data sheet says the material decomposes in contact with humidity and hydrolyses rapidly. Hydrogen is released.
- label: Heat
line: The data sheet gives a thermal decomposition at about 800 °C and a hydrogen equilibrium pressure of 0.09 mbar at 500 °C, rising to about 1,010 mbar at 850 °C.
- title: Handling and storage
points:
- label: Atmosphere
line: Albemarle says to handle the powder under an inert gas atmosphere and to store it in tightly closed containers, excluded from humidity.
- label: Transport
line: UN 1414, class 4.3, packing group I, as printed by Albemarle for road, rail, sea and air transport.
why: Lithium hydride (LiH) is a lithium compound with a high hydrogen content. Albemarle's technical data sheet gives a density of 0.78 g/cm3 and a melting point of 688 °C, and says that the powder decomposes in contact with humidity. NASA's 1969 shield study found LiH to be one of the best neutron shield materials for a space power reactor. A later NASA paper calls it the most effective neutron shield per unit mass, but it sets LiH aside because a simple cooling model could not keep the shield within temperature limits.
uses:
- where: Space reactor radiation shields
line: NASA's 1969 ground study of a 2.2 MW-thermal fast-spectrum reactor found an optimized shield weight of 25 300 kg with depleted uranium and 28 500 kg with tungsten. Both designs used natural lithium hydride as the neutron shield, in four layers alternated with three metal layers.
- where: Nuclear thermal propulsion shielding
line: A later NASA shielding paper says lithium hydride is the most effective neutron shield per unit mass, but its poor thermal conductivity makes cooling nearly impossible in a high-flux reactor. The study chose a boron carbide pebble bed instead.
- where: Chemistry
line: Albemarle sells lithium hydride as a reducing agent, a high-density hydrogen source and a raw material for high-purity monosilanes. These are terrestrial industrial uses, not space applications.
can_do:
- label: Density
benchmark: density
line: Lithium hydride powder has a density of 0.78 g/cm3 at 20 °C, per the Albemarle data sheet. Its bulk density is 290 to 400 kg/m3 as a powder.
- label: Hydrogen content
benchmark: theoretical_hydrogen_content
value: 12.7 %
line: The theoretical hydrogen content is 12.7 %, and the data sheet gives 2.82 litres of hydrogen evolved per gram of LiH in hydrolysis. This is the figure behind its use as a high-density hydrogen source.
- label: Melting point
benchmark: melting_point
value: 688 °C
line: The data sheet gives a melting point of 688 °C and a thermal decomposition at about 800 °C.
- label: Purity
benchmark: assay
value: 97 %
line: The supplier specification is a minimum of 97 % LiH, with sodium at most 0.9 % and potassium at most 0.05 %.
compare: Lithium hydride is the most effective neutron shield per unit mass in NASA's reactor-shield studies, but its cooling is difficult. The NASA shielding paper by Caffrey and colleagues says a boron carbide shield has a mass penalty of about 20 % greater than a practical LiH shield, and that boron carbide has excellent thermal conductivity, hardness and chemical stability. The table compares LiH with the reference points in this profile.
compare_rows:
- label: Density
benchmark: density
- label: Melting point
benchmark: melting_point
- label: Hydrogen content
benchmark: theoretical_hydrogen_content
handling:
- Handle the powder under an inert gas atmosphere, away from water and humidity (Albemarle).
- Store in tightly closed containers, dry, cool and separated from incompatible materials (Albemarle and ICSC 0813).
- Avoid dust. In use the powder may form flammable or explosive dust-air mixtures, and Albemarle says to avoid inhalation.
- Retest the material 6 months after the analysis date (Albemarle).
good_for:
- Neutron shielding by mass. NASA's studies call LiH the most effective neutron shield per unit mass (NASA shielding paper).
- Hydrogen-dense powder. The theoretical hydrogen content is 12.7 %, and Albemarle sells the powder as a high-density hydrogen source.
watch_out:
- Water and humid air. The powder hydrolyses rapidly and releases flammable gas (H260).
- Poor thermal conductivity. NASA says LiH is hard to cool in a high-flux reactor shield.
- Corrosive and toxic if swallowed. ICSC 0813 and PubChem describe the powder as corrosive (H314) and toxic (H301).
verdict: Lithium hydride is the hydrogen-rich neutron shield that NASA's studies rate highest per unit mass, but it must be kept dry and sealed, and it is hard to cool in a reactor. Its use in space shielding has been studied on paper and in ground analysis, and no flight result was found.
References
Every number above carries a reference number. Click one to see the source and where in it the value comes from.
| # | Source | Type | Year | Used for |
|---|---|---|---|---|
| Technical Data Sheet: Lithium Hydride, powder < 100 µm (Albemarle, product 10000103) | datasheet | 2025 | 19 values | |
| Comparison of Tungsten and Depleted Uranium in Minimum-Weight, Layered Shields for a Space Power Reactor (NASA TM X-1874, Lahti and Herrmann) | report | 1969 | 4 values | |
| Shielding Development for Nuclear Thermal Propulsion (Caffrey, Gomez, Scharber) | paper | 4 values | ||
| ICSC 0813: Lithium hydride, International Programme on Chemical Safety | handbook | 4 values | ||
| PubChem compound record, Lithium hydride (CID 62714) | database | 2026 | 1 value | |
| Mineral Commodity Summaries 2026: Lithium | report | 2026 | 1 value | |
| IUPAC CIAAW standard atomic weight of lithium | database | 2009 | 0 values | |
| IUPAC CIAAW standard atomic weight of hydrogen | database | 2009 | 0 values |
Updated