The UN number 3131 designates a WATER-REACTIVE SOLID, CORROSIVE, N.O.S. (Not Otherwise Specified). This classification identifies a hazardous material that reacts dangerously with water and also possesses corrosive properties, used when the specific substance is not listed under a more precise UN entry.
Understanding UN Number 3131
UN numbers are universal four-digit codes established by the United Nations to identify hazardous materials during transportation. They are crucial for consistent identification and safe handling across different modes of transport globally. UN 3131 specifically categorizes a substance that presents a dual hazard profile.
Here's a detailed breakdown of what UN 3131 signifies:
| Attribute | Description |
|---|---|
| UN Number | 3131 |
| Proper Shipping Name | WATER-REACTIVE SOLID, CORROSIVE, N.O.S. |
| Primary Hazard Class | 4.3 (Water-Reactive Substances): These are solid materials that, upon contact with water, can become spontaneously flammable or produce flammable gases in hazardous quantities. This reaction often generates significant heat, increasing the risk of fire or explosion. |
| Subsidiary Risk | 8 (Corrosive Substances): These substances are capable of causing severe damage to living tissue (like skin or eyes) upon contact, or can materially damage, or even destroy, other freight or transport equipment in the event of leakage. |
| Special Provision | N.O.S. (Not Otherwise Specified): This designation indicates that the entry is a generic description used for substances, mixtures, or articles that meet the defined hazard criteria (water-reactive and corrosive in this case) but are not explicitly named in the dangerous goods regulations. When using an N.O.S. entry, additional technical names identifying the specific substance must be provided on shipping documents. |
Key Characteristics Explained
Materials classified under UN 3131 are particularly dangerous due to their combined hazards:
- Water-Reactive Solid (Class 4.3): The primary danger lies in their vigorous reaction with water. This can lead to:
- Generation of flammable gases (e.g., hydrogen, acetylene).
- Potential for spontaneous ignition or explosion of these gases.
- Significant heat release during the reaction.
- Corrosive (Class 8): The subsidiary risk highlights the substance's ability to:
- Cause severe chemical burns to skin, eyes, and mucous membranes.
- Corrode metals and other materials, potentially compromising containers or surrounding structures.
Importance in Transport and Safety
The specific classification of UN 3131 is vital for ensuring the safe handling, storage, and transportation of these hazardous materials. It dictates a range of critical safety measures:
- Specific Packaging: Substances under UN 3131 require specialized packaging designed to prevent any contact with moisture and to withstand corrosive effects.
- Distinct Labeling and Placarding: Packages and transport vehicles must display clear warning labels and placards for both Class 4.3 (water-reactive) and Class 8 (corrosive) hazards, immediately informing all personnel of the dangers.
- Strict Segregation: These materials must be meticulously segregated from water sources and incompatible substances (such as certain acids, bases, or oxidizing agents) to prevent dangerous reactions.
- Emergency Response Protocols: In the event of an incident like a spill or fire, the UN 3131 classification provides immediate guidance for emergency responders, including:
- Avoiding the use of water for firefighting or spill cleanup.
- Requiring appropriate personal protective equipment (PPE) to protect against chemical burns and inhalation hazards.
- Implementing specific containment and neutralization strategies.
For comprehensive regulatory details on the transport of UN 3131, including packing instructions and handling precautions, refer to official dangerous goods regulations such as the ADR (European Agreement concerning the International Carriage of Dangerous Goods by Road) or the IMDG Code (International Maritime Dangerous Goods Code).
