Hexylene glycol

Hexylene glycol consists of a pentane main chain, which has two hydroxy groups and a methyl radical. The functional groups are not attached to the terminal but to the penultimate carbon atoms on both sides of the molecule. The methyl radical is also attached to one of these two carbon atoms. The structure is expressed in the synonymous designation 2-methyl-2,4-pentanediol.

Hexylene glycol exists in two isomeric forms. These differ in the spatial arrangement of the hydroxy group on the fourth carbon atom and are referred to as (R)-hexylene glycol and (S)-hexylene glycol. The compound is supplied as a racemic mixture with a balanced proportion of the two isomers.

Hexylene Glycol is a colorless liquid with a mild, sweet odor. It has high viscosity and low volatility. The compound is compatible with both polar and non-polar substances and is miscible with water, ethanol, diethyl ether and fatty acids. However, it is only slightly soluble in carbon tetrachloride. Hexylene glycol has the surface-active property of a surfactant and is suitable for stabilizing emulsions.

Hexylene glycol is stable under normal conditions. However, the compound can react violently with strong reducing agents, strong acids, oxidizing agents, isocyanates and nitric acid. It should be stored in tightly closed containers at room temperature.

Hexylene glycol is flammable but difficult to ignite. Its vapors can form explosive mixtures with the ambient air. Although the vapor pressure of the compound is low at room temperature, there is a risk of explosion, particularly if heated above the flash point. Proximity to sources of ignition such as open flames and welding sparks must be avoided at all costs. When hexylene glycol is heated to the point of decomposition, acrid and noxious gases are released.

Hexylene glycol is irritating to the respiratory tract, skin and eyes. Affected parts of the body should be rinsed thoroughly under running water. Medical treatment must be arranged. The compound can cause significant irritation and allergic reactions, especially on damaged skin. Hexylene glycol can be absorbed through damaged skin and can lead to serious symptoms of poisoning such as organ damage to the kidneys and liver.

Undiluted hexylene glycol is harmful to the eyes if it comes into direct contact. In tolerance studies on animals, the compound caused considerable irritation of the eyes and damage to the cornea that was difficult to heal.

Hexylene glycol is considered to be slightly hazardous to water. Entry of the substance into the ground, water bodies or the sewage system must be avoided.