The flash point of acetone is −20 °C (−4 °F), which is equivalent to 253 K.
This low flash point indicates that acetone is a highly flammable substance. The flash point represents the lowest temperature at which a liquid can produce enough flammable vapor to ignite if an ignition source is present. At or above this temperature, a sufficient concentration of flammable vapor exists in the air near the liquid's surface to allow for combustion.
Key Flammability Properties of Acetone
Understanding the flammability characteristics of acetone is essential for its safe handling and storage. Beyond its flash point, other critical properties include:
| Property | Value |
|---|---|
| Flash Point | −20 °C (−4 °F; 253 K) |
| Autoignition Temperature | 465 °C (869 °F; 738 K) |
| Explosive Limits | 2.5–12.8% (Volume in air) |
- Flash Point: As established, this is the minimum temperature at which acetone forms an ignitable vapor-air mixture. A substance with a flash point below 23 °C (73 °F) is typically classified as highly flammable or extremely flammable.
- Autoignition Temperature: This is the temperature at which acetone will spontaneously ignite in the air without any external ignition source, such as a spark or flame.
- Explosive Limits (Flammable Limits): These define the concentration range of acetone vapor in the air within which an explosion can occur if an ignition source is introduced. The lower explosive limit (LEL) for acetone is 2.5%, and the upper explosive limit (UEL) is 12.8%. A wide range between the LEL and UEL indicates a higher risk of fire or explosion.
Safety Implications and Handling Precautions
Due to its low flash point and wide explosive limits, acetone demands strict safety protocols to prevent fire and explosion hazards.
- Ventilation: Always use acetone in well-ventilated areas or under a fume hood to prevent the accumulation of flammable vapors.
- Eliminate Ignition Sources: Keep acetone away from all potential ignition sources, including open flames, sparks, hot surfaces, static electricity, and even friction.
- Proper Storage: Store acetone in tightly closed containers in a cool, dry, and well-ventilated area, away from direct sunlight and incompatible materials.
- Personal Protective Equipment (PPE): Wear appropriate chemical-resistant gloves and eye protection (e.g., safety goggles or a face shield) to prevent skin contact and eye exposure.
- Fire Extinguishing Media: Be aware of suitable fire extinguishing agents for acetone fires, such as alcohol-resistant foam, carbon dioxide, or dry chemical extinguishers.
Adhering to these safety measures is crucial for mitigating the risks associated with handling this common, yet highly flammable, solvent.
