Acetone, also known as propanone, is a colorless, organic compound commonly recognized as a potent solvent and a primary ingredient in many nail polish removers. It is highly effective because it rapidly dissolves substances like plastics, resins, and paints. Due to its chemical properties, attempting to microwave acetone is extremely hazardous and should not be done.
Why Heating Acetone Is Extremely Dangerous
Microwaving acetone creates an immediate and severe safety risk because the chemical is incompatible with the appliance’s rapid heat transfer mechanism. Microwave ovens generate electromagnetic waves that cause polar molecules to vibrate intensely, quickly generating thermal energy. Acetone is a polar molecule, but its low boiling point means that even minimal microwave energy can cause its temperature to spike uncontrollably. This rapid heating quickly pushes the liquid toward its boiling point of approximately 56 degrees Celsius (133 degrees Fahrenheit). The uncontrolled temperature increase accelerates the conversion of liquid acetone into a highly concentrated vapor within the enclosed microwave cavity.
Acetone’s Flammability and Volatility
The inherent flammability of acetone is why heating it is perilous. Acetone is classified as a highly volatile organic compound, meaning it readily evaporates even at room temperature. Its flash point—the minimum temperature at which a liquid gives off enough vapor to form an ignitable mixture with air—is extremely low, resting at about -20 degrees Celsius (-4 degrees Fahrenheit). This means that acetone produces highly flammable vapor in dangerous concentrations far below typical indoor temperatures. When the liquid is heated in a microwave, the rate of vaporization increases exponentially, quickly filling the appliance with an explosive atmosphere. This vapor becomes flammable when it constitutes between 2.5 and 12.8 percent of the air volume.
The Immediate Risks of Microwaving Solvents
Placing acetone in a microwave presents immediate, severe hazards to both property and health. The most significant danger is the massive explosion risk caused by the vapor buildup inside the sealed microwave chamber. When the highly flammable acetone vapor is trapped, it quickly reaches its explosive concentration limits and creates intense pressure.
The fire hazard is triggered by the internal components of the microwave oven, which are not designed to operate in an explosive atmosphere. Sparks are naturally generated by the magnetron and other electrical switches during normal operation. When these small electrical arcs encounter the concentrated, explosive acetone vapor, the result is an immediate flash fire or explosion that can rupture the microwave and spread fire to the surrounding area. Furthermore, the rapid heating creates a significant inhalation hazard from concentrated toxic fumes. While not acutely toxic in small quantities, heating acetone generates a high concentration of vapor that can cause severe respiratory irritation, dizziness, and central nervous system effects.