Methane
| Chemical name | Methane |
|---|---|
| Common names / synonyms | R50, HC-50, Marsh gas, Methyl hydride, primary component of natural gas |
| CAS number | 74-82-8 |
| UN number | 1971 (Methane, compressed) |
| Dangerous goods code | Class 2.1 Flammable gas |
| Molecular formula | CH4 |
| Molecular weight | 16.04 g/mol |
| Recommended use | Ultra-low temperature refrigerant (cascade system low-temperature stage), primary component of natural gas, chemical feedstock (syngas, hydrogen, methanol production), fuel |
| Supplier name | Anhui Kelvins Refrigeration Technology Co., Ltd. |
|---|---|
| Address | Room 302, Building B, No. 396 Songgu Road, Hefei, China |
| Postal code | 230601 |
| Telephone | +86 551 6558 9290 |
| Fax | +86 551 6558 9290 |
| sales@klven.cn |
National Chemical Emergency Hotline (China): +86-532-83889090 (24 hours)
Supplier Emergency Contact: +86 551 6558 9290
Signal word: Danger
This product is a pure substance.
| Component name | CAS No. | Concentration (by mass) |
|---|---|---|
| Methane | 74-82-8 | ≥99.5% (refrigerant grade) |
| Impurity | Specification limit |
|---|---|
| Moisture | ≤10 ppm |
| Acidity (as HCl) | ≤1 ppm |
| Evaporation residue | ≤100 ppm |
| Non-condensable gas (25°C, vol%) | ≤1.5% |
| Other hydrocarbons (ethane, propane, etc.) | ≤0.5% |
| Sulfur compounds | ≤1 ppm |
Note: Refrigerant-grade methane has higher purity than pipeline natural gas and is specifically for ultra-low temperature cascade refrigeration systems.
General advice: Remove victim from contaminated area immediately. Keep warm and at rest. Show this SDS to attending physician. Caution: Confirm no explosion hazard and eliminate all ignition sources before entering the leak area.
Inhalation:
Skin contact (frostbite):
Eye contact:
Ingestion:
Not applicable. This substance is a gas at ambient temperature; ingestion exposure is not expected.
Suitable extinguishing media: Dry chemical, carbon dioxide, water fog (for cooling containers). For large gas fires, the preferred approach is to stop the gas flow first, then extinguish.
Unsuitable extinguishing media: Direct water streams (may spread the flame and enlarge the accident area).
Carbon dioxide (CO₂), water (H₂O), carbon monoxide (CO, from incomplete combustion).
See Section 8 (Exposure controls/personal protection) and Section 13 (Disposal considerations).
For industrial use only. Personnel must be professionally trained. Primarily used as ultra-low temperature refrigerant in cascade refrigeration system low-temperature stage. Do not use for direct food contact, medical inhalation, or other unapproved applications.
| China OEL (Occupational Exposure Limit) | No established legal limit. Methane is a simple asphyxiant; recommended control benchmark: oxygen content not less than 18% |
|---|---|
| ACGIH TLV-TWA (USA) | No specific TLV established (simple asphyxiant); reference limit: 1000 ppm (based on alkane gases) |
| OSHA PEL-TWA (USA) | No specific limit established (simple asphyxiant) |
| Simple asphyxiant limit | Atmospheric oxygen content should be maintained at 19.5%~23.5% (normal air contains approximately 20.9% oxygen) |
| Biological limit value | Not established |
Note: Methane acts as a simple asphyxiant; its hazard mechanism is displacement of oxygen in air leading to hypoxia, not chemical toxicity. The primary monitoring indicators are workplace oxygen content and combustible gas concentration (LEL).
Combustible gas detector (catalytic combustion or infrared type, measuring LEL%); gas chromatography (GC-FID or GC-MS); oxygen monitor (electrochemical sensor).
Respiratory protection:
Eye/face protection:
Skin protection:
| Appearance and odor | Colorless, odorless gas; gaseous at ambient temperature and pressure; colorless transparent liquid under pressure (critical temperature -82.6°C, cannot be liquefied at room temperature) |
|---|---|
| Odor threshold | Odorless (pure methane has no odor; natural gas is odorized for leak detection; refrigerant grade is not odorized) |
| pH | Not applicable (gas) |
| Melting point / Freezing point | -182.5 °C (-296.5 °F) |
| Boiling point / Boiling range (101.3 kPa) | -161.5 °C (-258.7 °F) |
| Flash point | -188 °C (-306.4 °F) |
| Evaporation rate | Not available |
| Flammability (gas) | Extremely flammable |
| Explosive limits (upper/lower) | Upper 15.0% / Lower 5.0% (by volume in air) |
| Vapor pressure (25°C) | Extremely high (supercritical state; critical temperature -82.6°C is below 25°C, saturated vapor pressure cannot be expressed; stored in cylinders as compressed gas) |
| Vapor density (air = 1) | ~0.55 (lighter than air) |
| Gas density (0°C, 1 atm) | 0.717 g/L |
| Relative density (liquid, at boiling point) | 0.422 g/cm³ (liquid density at boiling point) |
| Solubility | Slightly soluble in water (~22 mg/L at 25°C); soluble in ethanol, ether, benzene, and other organic solvents |
| Octanol/water partition coefficient (log P) | ~1.09 |
| Auto-ignition temperature | 537 °C (999 °F) |
| Decomposition temperature | >1000 °C onset of thermal decomposition |
| Viscosity (gas, 25°C) | ~11.2 μPa·s |
| Surface tension (liquid, at boiling point) | ~16.6 mN/m |
| Thermal conductivity (gas, 25°C) | 0.0346 W/(m·K) |
| Critical temperature | -82.6 °C (-116.7 °F) — below room temperature; supercritical state at 25°C |
|---|---|
| Critical pressure | 4599 kPa (4.59 MPa / 667 psia) |
| Critical density | 0.162 g/cm³ |
| Heat of vaporization (at boiling point) | 510 kJ/kg |
| Liquid specific heat (at boiling point) | 3.48 kJ/(kg·°C) |
| Gas specific heat (25°C, constant pressure) | 2.22 kJ/(kg·°C) |
| Net heat of combustion | 50.0 MJ/kg |
| ASHRAE safety group | A3 (low toxicity, high flammability) |
|---|---|
| Ozone Depletion Potential (ODP) | 0 (does not deplete ozone layer; see Section 12.6) |
| Global Warming Potential (GWP, 100-yr) | ~28 (relative to CO₂ = 1; see Section 12.6) |
Chemically stable under normal temperature and pressure conditions; not readily reactive. Can react with halogens and strong oxidizing agents at elevated temperatures.
Stable under normal conditions of temperature and pressure. However, it is an extremely flammable gas that ignites on contact with any ignition source.
High temperature, open flame, sparks, static electricity, direct heat sources, cylinder overpressure, contact with strong oxidizing agents
Strong oxidizing agents (liquid oxygen, fluorine, chlorine, peroxides, etc.), halogens, strong acids, alkali metals
High-temperature cracking can produce hydrogen (H₂) and carbon (C). Incomplete combustion produces carbon monoxide (CO).
Will not occur.
Acute toxicity:
| Rat inhalation LC50 (4 hr) | >500,000 ppm (essentially non-toxic, highest concentration tested) |
|---|---|
| Mouse inhalation LC50 (2 hr) | >500,000 ppm |
| Rabbit dermal LD50 | Not available (gaseous substance) |
Methane is a simple asphyxiant and is essentially non-toxic. Acute toxic effects are primarily caused by oxygen deprivation (asphyxiation).
No skin irritation/corrosion in gaseous state. Liquid contact can cause frostbite (physical injury), but is not a chemical corrosive.
No eye irritation/corrosion in gaseous state. Liquid contact can cause severe frostbite and corneal damage.
No sensitization reported. Available data show no sensitization effect.
Available test data show no mutagenic effect. Methane is a saturated alkane with stable chemical properties; it does not react with DNA.
No evidence of carcinogenicity.
No reproductive toxicity data. Methane is a simple asphyxiant; no reproductive toxicity is expected. Hypoxia from high-concentration exposure may indirectly affect fetal development.
Repeated low-concentration exposure shows no significant target organ toxicity. Methane is chemically stable and does not bioaccumulate.
Not expected to cause aspiration pneumonia in gaseous form. However, high-concentration inhalation can cause asphyxiation and death in severe cases. Methane itself does not cause chemical lung injury.
| Fish acute toxicity (LC50, 96 hr) | Not available (gas has extremely low water solubility; expected to be of low toxicity to aquatic organisms) |
|---|---|
| Daphnia acute toxicity (EC50, 48 hr) | Not available |
| Algae growth inhibition (EC50, 72 hr) | Not available |
| Bacterial toxicity | Not available |
log P = 1.09. Low bioaccumulation potential (below the bioconcentration threshold of log P = 4.5).
Highly volatile in gaseous form; extremely low water solubility. Volatilizes readily to atmosphere when released to soil. Methane can be produced by methanogenic bacteria and consumed by methanotrophic bacteria in soil.
Does not meet PBT (persistent, bioaccumulative, and toxic) / vPvB (very persistent and very bioaccumulative) criteria.
Product/residues:
Contaminated packaging:
1971 (Methane, compressed)
METHANE, COMPRESSED
Class 2.1 Flammable gas
Not applicable (Class 2 gases are not assigned a packing group)
Road transport (ADR):
Rail transport (RID):
Marine transport (IMDG Code):
Air transport (ICAO/IATA DGR):
International regulations:
Chemical Safety Assessment has not been carried out for this substance in the context of this SDS. Users should conduct their own assessment based on specific use conditions.
| Abbreviation | Full term |
|---|---|
| SDS / MSDS | Safety Data Sheet / Material Safety Data Sheet |
| GHS | Globally Harmonized System of Classification and Labelling of Chemicals |
| CAS | Chemical Abstracts Service (registry number) |
| UN | United Nations (dangerous goods number) |
| ODP | Ozone Depletion Potential |
| GWP | Global Warming Potential |
| LC50 | Lethal Concentration, 50% |
| LD50 | Lethal Dose, 50% |
| TLV-TWA | Threshold Limit Value - Time-Weighted Average |
| PEL | Permissible Exposure Limit |
| SCBA | Self-Contained Breathing Apparatus |
| PBT | Persistent, Bioaccumulative, and Toxic |
| LEL | Lower Explosive Limit |
| UEL | Upper Explosive Limit |
| BLEVE | Boiling Liquid Expanding Vapor Explosion |
| IPCC | Intergovernmental Panel on Climate Change |
This Safety Data Sheet (SDS) has been prepared in accordance with the UN GHS standard and applicable regulatory requirements. The information contained herein is based on publicly available chemical databases, technical literature, and national standards, and is believed to be accurate and complete as of the date of issuance. However, no warranty, express or implied, is made as to the absolute accuracy, completeness, or reliability of the information. Users should verify the applicability of the information for their specific use conditions and refer to the official SDS provided by the manufacturer/supplier for compliance purposes. The information in this document may be updated as new research findings and regulatory changes become available; periodic review of the latest version is recommended.
This Safety Data Sheet (SDS) is compiled by Kelvins for technical reference, prepared in accordance with GB/T 16483 and GB/T 17519. For the official SDS and batch inspection report, please contact us. If any data on this page is inconsistent with the manufacturer’s latest published version, the manufacturer’s official document shall prevail.
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