General Assist Safety Reference
Material Safety Data Sheet - R32
Difluoromethane refrigerant gas: hazards, first aid, handling and emergency controls
Based on Chemwatch MSDS 4077-96, Version 4, issued 3 June 2011
Extreme fire hazard: R32 is an extremely flammable compressed gas. It can form explosive mixtures with air, and cylinders may rupture if exposed to heat or fire.
Important: This article is a practical summary only. Always use the current supplier Safety Data Sheet, site risk assessment, applicable legislation and emergency procedures before handling R32.
1. Product identification
| Product name | R32 refrigerant gas |
| Chemical name | Difluoromethane |
| Synonyms | HFC-32, CH2F2, Freon 32, Genetron 32, methylene fluoride |
| CAS number | 75-10-5 |
| Supplier shown on source MSDS | Technochem, Melton, Victoria, Australia |
| Intended use | Refrigerant and aerosol propellant |
| Ozone depletion potential | Nil (0.00) |
2. Hazard identification
Hazard alert code: EXTREME
Classification in the source MSDS: Dangerous goods; non-hazardous substance according to the NOHSC criteria and ADG Code current at the time of issue.
Classification in the source MSDS: Dangerous goods; non-hazardous substance according to the NOHSC criteria and ADG Code current at the time of issue.
- Extremely flammable: readily ignited by heat, sparks or flame and forms explosive mixtures with air.
- Pressurised container: cylinders may rupture or vent when heated.
- Asphyxiation risk: vapour is heavier than air and can displace oxygen in pits, basements and confined spaces.
- Health effects: high concentrations may cause headache, dizziness, drowsiness, reduced coordination, narcosis, irregular heartbeat, unconsciousness or death.
- Cold injury: contact with liquid refrigerant may cause frostbite.
- Skin effects: repeated exposure may cause dryness, cracking or irritation.
Composition
| Component | CAS number | Concentration |
|---|---|---|
| Difluoromethane | 75-10-5 | Greater than 99% |
3. First aid measures
| Exposure | Action |
|---|---|
| Inhalation | Remove the person from the contaminated area to fresh air without placing the rescuer at risk. Provide rescue breathing if required. Administer oxygen by trained personnel and seek urgent medical attention. |
| Eye contact | Move away from the gas source and rinse with clean, cool water for at least 15 minutes while holding the eyelids open. Obtain medical advice if symptoms continue. |
| Skin contact | Remove contaminated clothing and flush the affected area with running water. Use soap if available. Seek medical attention for irritation or cold injury. |
| Frostbite | Gently warm the affected area in a water bath at 41-46°C for 15-20 minutes. Do not rub the affected tissue. Seek urgent medical care. |
| Ingestion | Not considered a normal route of exposure because the product is a gas. |
Medical personnel: The source MSDS advises avoiding adrenaline/epinephrine and other sympathomimetic medicines where cardiac sensitisation is suspected. Treatment decisions must be made by qualified medical professionals.
4. Fire fighting and accidental release
Fire response
- Do not extinguish burning gas unless the leak can be safely stopped. Uncontrolled gas flow may create an explosive re-ignition risk.
- For a small fire, dry chemical, carbon dioxide or water spray may be used only when it is safe and necessary.
- Do not use a direct water jet on the leak or safety device.
- Cool fire-exposed cylinders with large quantities of water from a protected location.
- Alert emergency services, evacuate as required and use self-contained breathing apparatus.
| Combustion products | Carbon monoxide, carbon dioxide, hydrogen fluoride and other decomposition products |
| Hazchem code | 2YE |
Leak or spill response
| 1 | Evacuate unprotected personnel and move upwind. |
| 2 | Eliminate ignition sources and increase ventilation where this can be done safely. |
| 3 | Do not enter pits, basements or confined spaces where gas may accumulate. |
| 4 | Use suitable respiratory protection, including positive-pressure self-contained breathing apparatus for major releases. |
| 5 | Do not apply excessive force to a leaking or damaged valve. |
5. Handling and storage
- Use closed, pressure-rated systems fitted with suitable temperature, pressure and relief controls.
- Use only in well-ventilated areas and provide mechanical ventilation where required.
- Earth equipment and lines to control static electricity.
- Do not transfer gas from one cylinder to another.
- Use equipment and containers compatible with the cylinder pressure and refrigerant.
- Keep valve protection caps fitted until the cylinder is secured and ready for connection.
- Store cylinders upright in a secure, well-ventilated purpose-built compound, preferably outdoors.
- Protect cylinders from sunlight, heat, weather, rust and physical damage.
- Restrict storage access to authorised personnel.
Material compatibility: The source MSDS states not to use aluminium or galvanised containers and identifies magnesium, aluminium and their alloys, brass and steel among materials requiring compatibility assessment. Use only manufacturer-approved refrigerant tools, cylinders, hoses and components.
6. Exposure controls and personal protective equipment
| Control | Requirement |
|---|---|
| Ventilation | Provide effective general or local exhaust ventilation. Use appropriately rated electrical equipment in areas where a flammable atmosphere may occur. |
| Respiratory protection | The source MSDS nominates a Type AX filter of sufficient capacity. For oxygen-deficient atmospheres, major leaks or confined spaces, use positive-pressure supplied-air or self-contained breathing apparatus as required by the risk assessment. |
| Eye protection | Safety glasses with side shields or chemical goggles. A face shield may be appropriate where liquid refrigerant release is possible. |
| Hand protection | Cloth or leather gloves when handling sealed and insulated cylinders. Use suitable cold-protection gloves where liquid refrigerant contact is possible. |
| Protective clothing | Closely fitted protective overalls. In higher-risk areas, use non-static clothing and non-sparking footwear. |
7. Physical and chemical properties
| Property | Value |
|---|---|
| Appearance | Colourless compressed gas with a sweet odour |
| Molecular weight | 52.03 |
| Boiling point | -52°C |
| Autoignition temperature | 648°C |
| Flammable range in air | 12.7% to 33.4% |
| Vapour pressure | 1705 kPa at 25°C |
| Relative vapour density | 1.8 (air = 1) |
| Water solubility | Partly miscible; approximately 0.44% at 25°C |
| Gas density | 34.6 g/L at 15°C |
8. Stability, health and environmental information
- Stable under normal recommended conditions.
- Avoid incompatible materials and oxidising agents.
- Hazardous polymerisation is not expected.
- Thermal decomposition may produce carbon monoxide, carbon dioxide and hydrogen fluoride.
- R32 has low bioaccumulation potential and high mobility in air.
- The source MSDS identifies inhalation as the principal occupational exposure route.
9. Disposal
- Recover refrigerant using approved equipment wherever practicable.
- Return cylinders to the supplier or an authorised refrigerant recovery facility.
- Do not release refrigerant deliberately to atmosphere.
- Ensure damaged or non-returnable cylinders are gas-free before authorised disposal.
- Dispose of residues and containers in accordance with current environmental and dangerous-goods requirements.
10. Transport information
| Mode | UN number | Class | Shipping name / notes |
|---|---|---|---|
| Land - ADG | 3252 | 2.1 | Difluoromethane (Refrigerant Gas R32); Hazchem 2YE |
| Air - IATA | 3252 | 2.1 | Passenger and cargo aircraft transport shown as forbidden in the source MSDS; cargo-only provisions apply. |
| Sea - IMDG | 3252 | 2.1 | Difluoromethane; EmS F-D, S-U |
11. Regulatory information
- Listed in the Australian Inventory of Chemical Substances in the source MSDS.
- Included in the Australian Customs prohibited exports regulations schedule for HFCs identified in the source document.
- No Poisons Schedule was assigned in the source MSDS.
12. Key safety summary
R32 is a flammable, pressurised refrigerant with a serious fire and asphyxiation risk if released. Safe work requires trained personnel, suitable ventilation, ignition control, compatible equipment, correct PPE and approved refrigerant recovery practices. Never work on an R32 system in a confined or poorly ventilated area without a documented risk assessment and appropriate controls.