Safety Data Sheet (SDS) - Methane (R50)

1.1 Product identifier

1.2 Details of the supplier of the safety data sheet

1.3 Emergency telephone number

National Chemical Emergency Hotline (China): +86-532-83889090 (24 hours)

Supplier Emergency Contact: +86-571-87024025

2.1 GHS classification

2.2 GHS label elements

Signal word: Danger

2.3 Other hazards

3.1 Substance/mixture

This product is a pure substance.

3.2 Composition information

3.3 Impurity information

Note: Refrigerant-grade methane has higher purity than pipeline natural gas and is specifically for ultra-low temperature cascade refrigeration systems.

4.1 Description of necessary first aid measures

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:

• Move victim to fresh air immediately. Keep airway clear.
• Administer oxygen if breathing is difficult.
• If not breathing, give artificial respiration (preferably with bag-valve-mask or pocket mask; avoid mouth-to-mouth).
• If no pulse, start cardiopulmonary resuscitation (CPR) immediately.
• Keep victim warm and at rest. Monitor condition closely.
• Seek medical attention immediately.

Skin contact (frostbite):

• Immediately flush affected area with large amounts of lukewarm water (37–40°C) to promote rewarming.
• Do NOT use hot water (>40°C) or direct heat (e.g., electric heaters).
• Do NOT rub or massage frostbitten area; this may worsen tissue damage.
• Carefully remove frozen clothing. If clothing sticks to skin, do NOT pull it off; cut around it.
• Cover with sterile dressing.
• Seek medical attention immediately.

Eye contact:

• Immediately hold eyelids open and rinse thoroughly with plenty of water or normal saline for at least 15 minutes.
• Ensure complete irrigation of all eye surfaces by lifting upper and lower lids.
• Remove contact lenses if present and easily removable.
• Seek medical attention immediately, preferably from an ophthalmologist.

Ingestion:

Not applicable. This substance is a gas at ambient temperature; ingestion exposure is not expected.

4.2 Most important symptoms and effects, both acute and delayed

• Acute inhalation: asphyxiation, dizziness, drowsiness, headache, nausea, ataxia, loss of consciousness. Oxygen levels below 18% can cause asphyxiation.
• Skin contact (liquid): frostbite (pale, hard skin, pain, blistering).
• Eye contact (liquid): severe frostbite, corneal damage, visual impairment.

4.3 Indication of any immediate medical attention and special treatment needed

5.1 Extinguishing media

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).

5.2 Special hazards arising from the substance or mixture

• Extremely flammable; forms explosive mixtures with air (explosive limits 5.0%~15.0% by volume).
• Vapor is lighter than air (approximately 0.55 times air density); accumulates at ceilings, rooftops, and high points, where it can flash back to the ignition source.
• Cylinders may rupture or explode when heated due to rapidly increasing internal pressure.
• Incomplete combustion produces carbon monoxide (CO), a toxic gas.
• Combustion in confined spaces can cause gas explosion.

5.3 Hazardous combustion products

Carbon dioxide (CO₂), water (H₂O), carbon monoxide (CO, from incomplete combustion).

5.4 Advice for firefighters

• Firefighters must wear positive-pressure self-contained breathing apparatus (SCBA) and full protective fire-resistant clothing.
• If a leaking gas is on fire, do NOT extinguish the flame unless the leak can be stopped safely. Continued burning prevents gas accumulation that could lead to a larger explosive mixture. Once the leak is stopped, the flame will extinguish itself.
• If possible, move containers from fire area to a safe location.
• Cool containers with water spray from a safe distance until fire is extinguished.
• Immediately evacuate if containers show discoloration or if pressure relief devices begin to vent.
• Isolate the area; keep unauthorized personnel out.
• Cool burning containers with large amounts of water from a distance; personnel must stay upwind.

6.1 Personal precautions, protective equipment and emergency procedures

• Evacuate personnel from the leak area to upwind locations immediately. Establish a perimeter and restrict access.
• Eliminate all ignition sources immediately: cut power, no open flame, no smoking, no use of non-explosion-proof equipment.
• Emergency responders should wear SCBA, anti-static clothing, cryogenic gloves, and eye protection.
• Enter from upwind direction.
• Stop leak if it can be done safely. If valve cannot be closed, move away from the leak point and wait for professional handling.
• Do not touch or walk through spilled material.
• Use non-sparking tools only.

6.2 Environmental precautions

• Prevent gas from entering sewers, basements, courtyards, or confined spaces.
• Ventilate the area to accelerate dispersion. Since methane is lighter than air, leaked gas will rise; accumulation at high points must be monitored.
• Minimize releases to control greenhouse gas emissions; recover whenever possible.
• Avoid release to atmosphere, waterways, or soil.

6.3 Methods and materials for containment and cleaning up

• Small leak: Increase ventilation to accelerate gas dispersion. Monitor combustible gas concentration (LEL) and oxygen levels to prevent explosion and asphyxiation.
• Large leak:
  • Close source valve if safe to do so.
  • Recover using dedicated gas recovery equipment.
  • If recovery is not possible, controlled burning may be used (requires professional personnel and equipment).
  • Use water fog/mist to dilute leaked gas (prevent water from entering sewers).
• Cylinder leak: Move cylinder to a well-ventilated safe area and vent slowly. If valve cannot be closed, contact supplier for professional handling.

6.4 Reference

See Section 8 (Exposure controls/personal protection) and Section 13 (Disposal considerations).

7.1 Precautions for safe handling

• Handle in closed systems with adequate natural ventilation or local exhaust. Since methane is lighter than air, exhaust vents should be positioned at high points.
• Personnel must be specially trained and strictly follow operating procedures. Certified personnel only.
• Prevent gas leakage into workplace atmosphere.
• Avoid contact with strong oxidizing agents (liquid oxygen, fluorine, chlorine, etc.).
• Handle cylinders carefully; do not drop, slide, roll, or bump cylinders.
• Equip area with leak emergency response equipment.
• No smoking, eating, or drinking in work areas.
• Wear insulated gloves and eye/face protection when handling liquid to prevent frostbite.
• Use explosion-proof ventilation systems and equipment.
• Periodically inspect cylinders, valves, and piping for leaks.
• All electrical equipment must meet the appropriate explosion-proof rating.
• Eliminate static electricity hazards; personnel must wear anti-static clothing and footwear.

7.2 Conditions for safe storage, including any incompatibilities

• Store in a cool, dry, well-ventilated flammable gas warehouse.
• Storage temperature should not exceed 30°C. Keep away from fire, heat sources, and direct sunlight.
• Store separately from oxidizers, halogens, and strong acids. Do not co-store with incompatible materials.
• Storage area should be equipped with leak emergency response equipment and combustible gas detectors.
• Cylinders must be stored upright with valve caps and safety rings in place, properly secured to prevent falling.
• Use explosion-proof lighting and ventilation systems.
• Prohibit use of equipment and tools that can generate sparks.
• Warehouse roof should be fitted with high-level exhaust vents, since methane is lighter than air and accumulates at high points.
• Post clear "No Open Flames" and "Explosion-Proof Zone" safety warning signs in storage areas.
• Implement two-person receiving/issuing and two-person custody system.

7.3 Specific end uses

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.

8.1 Control parameters

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).

8.2 Exposure monitoring methods

Combustible gas detector (catalytic combustion or infrared type, measuring LEL%); gas chromatography (GC-FID or GC-MS); oxygen monitor (electrochemical sensor).

8.3 Appropriate engineering controls

• Enclosed process design with general ventilation or local exhaust. Exhaust vents at high points since methane is lighter than air.
• Provide safety shower and eyewash station.
• Install combustible gas detection alarms in areas where large leaks may occur (detectors at both high and low points).
• Use explosion-proof electrical equipment meeting the appropriate rating.
• Install oxygen monitoring and alarm devices.

8.4 Individual protection measures

Respiratory protection:

• Normal conditions (below exposure limit, normal oxygen): no special protection required.
• Elevated concentrations or oxygen-deficient atmosphere: positive-pressure self-contained breathing apparatus (SCBA) or supplied-air respirator must be worn.
• Emergency rescue/evacuation: positive-pressure SCBA must be worn.

Eye/face protection:

• General handling: safety goggles.
• When handling liquid or potential liquid exposure: chemical safety goggles or face shield must be worn to prevent frostbite.

Skin protection:

• Hand protection: general work gloves for normal handling; cryogenic-insulated gloves for liquid contact.
• Body protection: anti-static work clothing; cold-resistant clothing for liquid contact.
• Other: no smoking in work areas; wear anti-static footwear to eliminate static hazards; use a buddy system when entering tanks, confined spaces, or other high-concentration areas with SCBA.

8.5 Hygiene measures

• Remove contaminated clothing and wash skin thoroughly after work.
• Maintain good personal hygiene.
• Ensure eyewash and emergency shower are available in the workplace.

9.1 Basic physical and chemical properties

9.2 Thermodynamic properties

9.3 Other safety data

10.1 Reactivity

Chemically stable under normal temperature and pressure conditions; not readily reactive. Can react with halogens and strong oxidizing agents at elevated temperatures.

10.2 Chemical stability

Stable under normal conditions of temperature and pressure. However, it is an extremely flammable gas that ignites on contact with any ignition source.

10.3 Possibility of hazardous reactions

• Forms explosive mixtures with air (explosive limits 5.0%~15.0%); can ignite or explode on contact with open flame or high heat.
• Reacts violently with strong oxidizing agents (liquid oxygen, fluorine, chlorine, hydrogen peroxide, etc.), causing combustion or explosion.
• Undergoes vigorous substitution reactions with halogens (chlorine, bromine) under light, producing halogenated hydrocarbons and large amounts of heat.
• Thermal decomposition at high temperatures (>1000°C) produces hydrogen and carbon (cracking).
• Under certain conditions (high temperature, catalyst), reacts with steam to produce carbon monoxide and hydrogen (syngas, reforming reaction).

10.4 Conditions to avoid

High temperature, open flame, sparks, static electricity, direct heat sources, cylinder overpressure, contact with strong oxidizing agents

10.5 Incompatible materials

Strong oxidizing agents (liquid oxygen, fluorine, chlorine, peroxides, etc.), halogens, strong acids, alkali metals

10.6 Hazardous decomposition products

High-temperature cracking can produce hydrogen (H₂) and carbon (C). Incomplete combustion produces carbon monoxide (CO).

10.7 Hazardous polymerization

Will not occur.

11.1 Information on toxicological effects

Acute toxicity:

Methane is a simple asphyxiant and is essentially non-toxic. Acute toxic effects are primarily caused by oxygen deprivation (asphyxiation).

11.2 Skin irritation/corrosion

No skin irritation/corrosion in gaseous state. Liquid contact can cause frostbite (physical injury), but is not a chemical corrosive.

11.3 Eye irritation/corrosion

No eye irritation/corrosion in gaseous state. Liquid contact can cause severe frostbite and corneal damage.

11.4 Respiratory or skin sensitization

No sensitization reported. Available data show no sensitization effect.

11.5 Germ cell mutagenicity

Available test data show no mutagenic effect. Methane is a saturated alkane with stable chemical properties; it does not react with DNA.

11.6 Carcinogenicity

No evidence of carcinogenicity.

• IARC (International Agency for Research on Cancer): Not listed
• ACGIH (American Conference of Governmental Industrial Hygienists): Not classified as a carcinogen
• EPA (U.S. Environmental Protection Agency): Not classified as a carcinogen

11.7 Reproductive toxicity

No reproductive toxicity data. Methane is a simple asphyxiant; no reproductive toxicity is expected. Hypoxia from high-concentration exposure may indirectly affect fetal development.

11.8 STOT-single exposure

• Asphyxiation (Category 3): High-concentration inhalation displaces oxygen in air, causing hypoxia. Symptoms include dizziness, drowsiness, headache, breathing difficulty, and loss of consciousness. Methane concentration of 10% in air can cause asphyxiation symptoms; oxygen content below 18% causes hypoxia symptoms; below 10% can rapidly cause death.
• Methane itself has no central nervous system depressant effect (unlike anesthetic gases); neurological symptoms result from hypoxia.

11.9 STOT-repeated exposure

Repeated low-concentration exposure shows no significant target organ toxicity. Methane is chemically stable and does not bioaccumulate.

11.10 Aspiration hazard

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.

12.1 Ecotoxicity

12.2 Persistence and degradability

• Atmospheric degradation: Primarily degraded by reaction with hydroxyl radicals (OH·); atmospheric lifetime ~12 years.
• Biodegradability: Can be oxidized to carbon dioxide and water by specific microorganisms (methanotrophic bacteria) under aerobic conditions.
• Hydrolysis: Not hydrolyzed at ambient temperature.
• Photodegradation: Atmospheric photochemical degradation (indirect photolysis via reaction with OH radicals).

12.3 Bioaccumulative potential

log P = 1.09. Low bioaccumulation potential (below the bioconcentration threshold of log P = 4.5).

12.4 Mobility in soil

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.

12.5 Results of PBT and vPvB assessment

Does not meet PBT (persistent, bioaccumulative, and toxic) / vPvB (very persistent and very bioaccumulative) criteria.

12.6 Other adverse effects

• Ozone Depletion Potential (ODP): 0 (does not deplete the ozone layer)
• Global Warming Potential (GWP, 100-year time horizon): ~28 (relative to CO₂ = 1)
• Methane is a potent greenhouse gas; its unit-mass warming effect is approximately 28 times that of CO₂ (100-year time horizon). It is a controlled greenhouse gas under the Kyoto Protocol and Paris Agreement.
• Large releases contribute to global warming; emissions should be controlled with priority on recovery and reuse.
• Not a controlled substance under the Montreal Protocol (ODS).

13.1 Waste treatment methods

Product/residues:

• Do NOT release directly to atmosphere (greenhouse gas, GWP = 28).
• Recovery and recycling (purification and reuse) is the preferred approach.
• If recovery is not feasible, controlled burning under safe conditions (requires professional personnel and equipment); combustion products are carbon dioxide and water.
• If recovery and burning are not feasible, dispose of through a licensed hazardous waste treatment facility.
• Do not discharge to sewers, waterways, or soil.

Contaminated packaging:

• Empty cylinders must be returned to supplier or a qualified facility for disposal. Do not discard or cut empty cylinders.
• Empty cylinders with residual pressure and gas are managed as hazardous waste.
• Do NOT cut, weld, or heat cylinders containing residual methane.

13.2 Special precautions for disposal

• Refer to national and local regulations before disposal (e.g., Solid Waste Pollution Prevention and Control Law, Hazardous Waste Storage Pollution Control Standards, etc.).
• Personnel should wear appropriate personal protective equipment (see Section 8).
• Ensure good ventilation to prevent asphyxiation and combustible gas accumulation.
• Disposal must be performed by a qualified and licensed facility.
• When burning, ensure no leak or explosion risk; have fire-fighting equipment available.
• Disposal records should be maintained.

14.1 UN number

1971 (Methane, compressed)

14.2 UN proper shipping name

METHANE, COMPRESSED

14.3 Transport hazard class(es)

Class 2.1 Flammable gas

14.4 Packing group

Not applicable (Class 2 gases are not assigned a packing group)

14.5 Packing mark / Hazard label

• Primary hazard label: Flammable gas (red, Class 2.1)
• Subsidiary hazard label: None

14.6 Methods and materials for containment and packaging

• Seamless steel cylinders. Cylinders must comply with applicable national standards (e.g., GB 5099).
• Common package sizes: 40 L, 50 L high-pressure cylinders (working pressure 15–20 MPa).
• Cylinder valve outlet thread direction: left-hand thread for flammable gases.
• Tube trailers (tube bundle containers) for bulk transport.

14.7 Special requirements for different modes of transport

Road transport (ADR):

• Vehicles must have hazardous cargo transport license; exhaust pipes must be fitted with spark arrestors.
• Cylinders must have valve caps and safety rings in place.
• Cylinders generally laid flat with valves pointing in same direction; do not stack crosswise. Height must not exceed vehicle guardrail.
• Transport during early morning/evening in summer to avoid direct sunlight.
• Follow designated routes; do not stop in residential or densely populated areas.
• ADR classification: 2.1F (flammable gas).

Rail transport (RID):

• Prohibit hump shunting (no free-roll classification).
• Transport in boxcars; cylinders upright or laid flat and secured.
• RID classification: 2.1F.

Marine transport (IMDG Code):

• UN 1971, Class 2.1
• Marine pollutant: No
• Stowage category: E (on deck only, away from living quarters)
• Flash point: -188°C

Air transport (ICAO/IATA DGR):

• UN 1971, Class 2.1
• Flammable compressed gas
• Passenger aircraft: Forbidden (Class 2.1 flammable gases prohibited on passenger aircraft)
• Cargo aircraft: Cargo aircraft only (subject to packing instruction 200 and quantity limits)

14.8 Special precautions for user

• Do not co-transport with oxidizers, halogens, strong acids, or food/feed products.
• Vehicles must be equipped with appropriate fire extinguishing equipment (dry chemical extinguishers) and leak emergency response gear.
• Transport personnel must be specially trained and certified.
• Protect from sunlight, rain, and high temperature during transit.
• When stopping en route, stay away from fire, heat sources, and high-temperature areas.
• Exhaust pipes of vehicles carrying this product must be fitted with spark arrestors.
• Load and unload carefully to prevent damage to cylinders and fittings.
• Vehicles should be equipped with combustible gas detection alarms.

15.1 Safety, health and environmental regulations/legislation specific for the substance or mixture

International regulations:

• UN GHS (Globally Harmonized System of Classification and Labelling of Chemicals): 8th revised edition
• Montreal Protocol: Not a controlled ozone-depleting substance (ODP = 0)
• Kyoto Protocol / Paris Agreement: Listed as greenhouse gas (methane is a major greenhouse gas, GWP = 28)
• EU REACH Regulation (EC 1907/2006): Registered substance
• EU CLP Regulation (EC 1272/2008): Classification, labelling and packaging regulation
• US OSHA HCS 2012: Hazard Communication Standard
• US DOT 49 CFR: Hazardous Materials Transportation Regulations (Class 2.1 flammable gas)
• ADR/RID: European Agreement concerning the International Carriage of Dangerous Goods by Road/Rail
• IMDG Code: International Maritime Dangerous Goods Code
• IATA DGR: International Air Transport Association Dangerous Goods Regulations
• UNFCCC (UN Framework Convention on Climate Change): Methane emission reduction is a global climate governance priority

15.2 Chemical safety assessment

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.

16.1 References

• NIOSH Pocket Guide to Chemical Hazards
• International Chemical Safety Card (ICSC) No. 1440
• NOAA CAMEO Chemicals Database
• PubChem Compound Database (CID 297)
• ASHRAE Handbook - Refrigeration Systems and Applications
• GB/T 16483-2008 (Content and order of sections in safety data sheet for chemical products)
• GB 30000 series (Rules for classification and labelling of chemicals)
• United Nations GHS (Globally Harmonized System of Classification and Labelling of Chemicals), 8th revised edition
• IPCC Fifth Assessment Report (AR5) - GWP reference

16.2 Abbreviations

16.3 Disclaimer

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.