Hexane is an organic molecule belonging to the alkane family of hydrocarbons. It is composed of six carbon atoms and fourteen hydrogen atoms (\(\text{C}_6\text{H}_{14}\)). It is primarily derived from the refining of crude oil, similar to gasoline, and its chemical nature makes it useful in many industrial processes and consumer products.
Physical Characteristics
In its standard state, hexane is a colorless liquid. While pure hexane is often described as odorless, commercial grades typically possess a mild, petrolic, or gasoline-like smell, which is due to the presence of closely related compounds. This chemical is highly volatile, linked to its low boiling point of approximately \(68^\circ\text{C}\) to \(69^\circ\text{C}\).
The liquid also exhibits low density, floating on water because it is insoluble in it. Hexane is extremely flammable, as it is considered a serious fire hazard. The vapors it produces are heavier than air, which allows them to travel along the ground and potentially ignite far from the source if they encounter a spark or open flame.
Industrial and Commercial Applications
The primary use of hexane stems from its nature as a non-polar solvent, making it effective at dissolving other non-polar substances like oils and fats. This property is widely utilized in the large-scale extraction of vegetable oils from seeds such as soybeans, canola, corn, and peanuts for food production. The solvent is applied to the crushed seeds to draw out the oil, and its low boiling point allows for relatively easy separation and recovery of the solvent afterward.
Commercial grades of hexane are found in industrial cleaning and degreasing operations. It is used as a cleaning agent in the printing, textile, and furniture industries to remove oils and residues. Furthermore, hexane is a component in several everyday consumer products, including glues, rubber cement, adhesives used in shoemaking and roofing, varnishes, and inks.
Basic Safety and Exposure
Due to its high volatility, the most common route of exposure to hexane is through the inhalation of its vapors. Short-term inhalation exposure to elevated levels can affect the central nervous system, leading to symptoms like lightheadedness, dizziness, mild nausea, and headaches. These effects are generally reversible upon moving to fresh air.
Repeated or long-term exposure to high concentrations has been associated with polyneuropathy. This involves damage to the peripheral nervous system, which can manifest as numbness, tingling sensations, and muscular weakness, particularly in the hands and feet. Handling the liquid requires proper ventilation and the use of personal protective equipment like gloves to prevent skin contact and inhalation.
Handling and Storage Safety
Because of its extreme flammability, hexane must be stored in tightly closed containers away from any heat source, sparks, or open flames. When handling the chemical, non-sparking tools are recommended to prevent the accidental ignition of the heavy vapors. Workplace exposure limits are established to minimize health risks.