Denatured alcohol, also known as methylated spirits, is a common solvent and fuel used in many household and industrial applications. It evaporates with extreme speed compared to many other common liquids. This rapid phase change from liquid to gas is a defining characteristic, influencing its effectiveness as a solvent and the necessary precautions for its safe use.
What Denatured Alcohol Is Made Of
Denatured alcohol is essentially ethyl alcohol, or ethanol, which has been intentionally rendered unsafe for human consumption. This process involves adding small amounts of highly toxic or foul-tasting chemicals called denaturants to the pure ethanol base. Common denaturants include methanol, isopropyl alcohol, acetone, and denatonium benzoate, which is added for its intense bitter taste.
The primary reason for denaturing the alcohol is to make it unpalatable or poisonous. This modification allows the product to be sold without the heavy excise taxes placed on consumable alcoholic beverages. By making the ethanol unfit to drink, manufacturers can offer a cheaper product for industrial uses, such as a fuel or a solvent. The addition of denaturants does not substantially change the physical properties of the ethanol, meaning the mixture retains the volatility of the pure alcohol.
Understanding Volatility and Evaporation Speed
The rapid evaporation of denatured alcohol is a result of its high volatility, a physical property directly related to its molecular structure. Volatility describes how easily a substance transitions from a liquid state to a gaseous state, which is measured by its vapor pressure and boiling point. Ethanol, the main component, has a relatively low boiling point of approximately 78 degrees Celsius, compared to water’s 100 degrees Celsius.
This lower boiling point indicates that the intermolecular forces holding the ethanol molecules together are weaker than the strong hydrogen bonds found between water molecules. Because less energy is required to break these bonds, the molecules escape into the air as vapor more readily, even at room temperature. At standard room temperature, the vapor pressure of ethanol is significantly higher than that of water. This difference means denatured alcohol can evaporate nearly three times faster than water under similar conditions.
Safe Handling Due to Rapid Evaporation
The speed at which denatured alcohol evaporates creates specific handling and safety concerns for users. As the liquid rapidly turns into a gas, it releases a high concentration of flammable vapor into the surrounding air. This accumulation of vapor presents a serious fire hazard, as it can travel along the floor and ignite explosively if it contacts an ignition source, such as a pilot light or a spark.
Proper ventilation is required when using the product to prevent the buildup of these flammable and potentially toxic vapors. Using denatured alcohol outdoors or in a well-ventilated space helps disperse the gas before it can reach dangerous concentrations. Containers must be kept tightly sealed when not in use, not only to prevent the product from evaporating but also to restrict the release of flammable vapor into storage areas. Always keep the liquid away from heat sources and open flames.