Material Safety Data Sheet (MSDS) for Compressed Natural Gas (CNG)
Identification
Product Name: Compressed Natural Gas (CNG)
Chemical Formula: CH4 (predominantly methane, with small amounts of ethane, propane, and other hydrocarbons)
Synonyms: Natural gas, Methane, CNG
Recommended Use: Fuel for vehicles, heating applications, industrial processes
Supplier: Natural gas distributors, local utility companies
Emergency Contact: Local fire department, gas supplier emergency line
Hazard Identification
Physical State: Compressed gas (odorless, colorless)
Hazard Classes: Flammable gas, Category 1
Hazard Statements: Extremely flammable gas; contains gas under pressure, explosion risk if heated
Routes of Exposure: Inhalation
Potential Health Effects: Asphyxiation in confined or poorly ventilated spaces; high exposure may lead to dizziness, headache, nausea
Label Elements: GHS02 (Flame), GHS04 (Gas cylinder), “Danger” signal word
Precautionary Statements: Keep away from heat, sparks, open flames; avoid breathing gas; use only outdoors or in well-ventilated areas
Composition / Information on Ingredients
Chemical Components: Methane (CAS 74-82-8, >95%), Ethane (CAS 74-84-0, 2–5%), Propane (CAS 74-98-6, <1%), Nitrogen (CAS 7727-37-9, varies), minor hydrocarbons
Impurities: Moisture, carbon dioxide, hydrogen sulfide (trace amounts, typically <0.05%)
First Aid Measures
Inhalation: Remove person from contaminated area to fresh air. Monitor breathing and pulse. If not breathing, begin artificial respiration and seek medical attention. Oxygen may be administered by trained personnel.
Eye Contact: Not anticipated to cause eye irritation under normal use. If contact with pressurized gas or liquefied gas occurs, flush eyes with water for at least 15 minutes and seek immediate medical attention for frostbite.
Skin Contact: Exposure to compressed or liquefied gas can cause frostbite; remove contaminated clothing and flush area with lukewarm water, never use hot water.
Ingestion: Not an expected route of exposure for gases.
Notes for Physicians: Treat symptomatically; monitor for simple asphyxiation.
Fire-Fighting Measures
Suitable Extinguishing Media: Dry chemical, CO2, water spray, fog
Special Hazards: Rapid burning or explosion possible if gas is ignited under pressure; releases flammable, possibly explosive mixtures with air
Firefighter Protection: Self-contained breathing apparatus and full protective gear
Specific Methods: Cut off gas supply if possible; cool containers exposed to fire with water spray; evacuate area if leak or fire cannot be controlled
Decomposition Products: Carbon monoxide, carbon dioxide, oxides of nitrogen under incomplete combustion
Accidental Release Measures
Personal Precautions: Evacuate area, eliminate ignition sources, ventilate enclosed spaces
Emergency Procedures: Warn occupants, contact emergency response, restrict entry
Environmental Precautions: Prevent discharge into confined or low-lying areas due to asphyxiation risk
Containment: Stop gas flow if safe; allow dispersal in open air from a safe distance
Cleanup Methods: Ventilate area thoroughly; monitor gas concentrations before reentry
Handling and Storage
Handling: No smoking, sparks, or open flames. Use in well-ventilated spaces to avoid asphyxiation. Avoid rough handling of cylinders.
Storage: Store in upright position secured against falling; designated areas labeled for flammable gas storage. Keep away from combustible materials and oxidizers. Protect from direct sunlight, temperatures above 50°C (122°F), and physical damage.
Special Requirements: Periodic leak testing, only trained personnel to handle high-pressure containers
Exposure Controls and Personal Protection
Occupational Exposure Limits: Methane – not established (simple asphyxiant); monitor oxygen levels
Engineering Controls: Exhaust ventilation, explosion-proof electrical equipment in the vicinity
Personal Protective Equipment: Eye protection for cylinder handling, gloves for frostbite protection, flame-resistant clothing in risk zones
Respiratory Protection: Approved supplied-air respirators for emergencies or oxygen-deficient situations
Hygiene Measures: Wash after handling gas, remove contaminated clothing
Physical and Chemical Properties
Physical State: Compressed, colorless, odorless gas
Odor Threshold: Odorless in pure form; mercaptan added for leak detection
Boiling Point: -161.5°C (methane)
Molecular Weight: 16.04 (methane)
Vapor Pressure: 3,800 kPa at 25°C
Solubility: Slight in water
Relative Density: 0.55 (air = 1)
Flammability: Explosive limits 5–15% in air
Autoignition Temperature: 537°C
Partition Coefficient: Not applicable
Appearance: Gas at standard temperature and pressure, compressed for transport and storage
Stability and Reactivity
Chemical Stability: Stable under normal storage and handling conditions
Conditions to Avoid: Exposure to open flame, high temperatures, electrical sparks
Incompatible Materials: Strong oxidizers (chlorine, oxygen, fluorine), halogens
Hazardous Decomposition: Carbon oxides, unburned hydrocarbons
Hazardous Polymerization: Not known to occur
Toxicological Information
Acute Toxicity: Methane classified as non-toxic but acts as a simple asphyxiant
Inhalation: Exposure can cause headache, dizziness, fatigue, nausea at 50–100% concentrations, unconsciousness or death without oxygen
Skin/Eye Contact: Not an irritant at ambient temperatures; liquefied gas can cause cryogenic burns/frostbite
Chronic Exposure: No known cancer, developmental, or reproductive risks
Exposure Symptoms: Simple asphyxiation symptoms, oxygen deprivation
Ecological Information
Ecotoxicity: Not directly toxic to aquatic or terrestrial species; rapid dispersal in atmosphere
Persistence and Degradability: Biodegrades in atmosphere, typical lifespan is about 12 years
Bioaccumulation Potential: No potential for bioaccumulation
Mobility in Soil: Highly mobile as a gas, will vent to atmosphere
Environmental Concerns: Powerful greenhouse gas; major emissions from leaks contribute to climate change
Disposal Considerations
Disposal Methods: Do not vent to confined spaces; allow controlled release to well-ventilated outdoor air away from ignition sources
Empty Containers: Ensure complete evacuation of gas before disposal; depressurize and recycle cylinders where possible
Regulatory Disposal Guidance: Follow national and local regulations for pressurized gas and hazardous waste
Special Precautions: Secure handling and isolation before disposal, prevent uncontrolled release
Transport Information
UN Number: UN1971
Proper Shipping Name: Natural gas, compressed
Hazard Class: 2.1 (flammable gas)
Packing Group: Not assigned for gases
Transport Labeling: Flammable gas, cylinder label
Special Precautions: Secure cylinders upright, protect valves, avoid impacts and heat
Transport Regulations: DOT (U.S.), ADR (Europe), local authorities set clear guidance on signage, placarding, and routing
Regulatory Information
Relevant Regulations: OSHA (U.S.) workplace standards, EPA emissions restrictions, DOT transportation rules, REACH and GHS labeling globally
Environmental Restrictions: Methane release restrictions, state and local air quality directives
Safety Requirements: Mandatory training, emergency plans, leak detection for storage and use, periodic inspection of pressure tanks
Labeling Obligations: Clear hazard labeling on vessels and cylinders, traceable tracking of deliveries
Workplace Requirements: Access to emergency first aid procedures, certified handling for pressure cylinders, use permits in many jurisdictions
