Benzyl Alcohol Toxicity
Benzyl alcohol is an organic, aromatic alcohol with a color that is water-white with a sharp burning taste and a low aromatic odor. Benzyl alcohol can be found naturally as being produced by a variety of plants and is used in essential oils, fruits and in teas. Because of its polarity, low vapor pressure and low toxicity, it is commonly used as a solvent for waxes, inks, paints, epoxy resin coatings, lacquers and shellacs. Other uses include as a rug cleaning degreaser, e-cigarette liquid, ingredient in soaps, flavors and perfumes. At 10% concentration, it behaves as a local anesthetic. While it is harmless in many instances, there are still toxicity issues to be aware of when it comes to benzyl alcohol.
At levels of 3% or higher, benzyl alcohol has been found to be a skin irritant. Studies have shown that the way that benzyl alcohol affects the immune system can cause human skin to react with responses that may include hives, burning, skin blistering, scaling and itching. Studies have revealed that repeated exposure can lead to contact dermatitis. These effects are more commonly found on individuals who already have reactive or sensitive skin in the first place. Benzyl alcohol is also considered an eye irritant and in its pure form creates corneal necrosis.
Because benzyl alcohol is similar to other types of preservatives, it may break down and make aldehydes when it is mixed with other chemicals. Formaldehyde can be one of the aldehydes, which is widely known carcinogen. While exposure levels are generally small, it is a fact that should be disclosed to those who are working with benzyl alcohol or have history of cancers. Prolonged exposure can also be harmful to the central nervous system and liver. In healthy individuals, benzyl alcohol quickly oxidizes to benzoic acid, joined with liver glycine and is excreted in the form of hippuric acid. Concentrations at very high levels can lead to toxic results that include vasodilation, respiratory failure, paralysis, hypotension and convulsions.
In animal studies, 10% benzyl alcohol was found to be a skin irritant to the hairless skin of guinea pigs after a 24-hour period. Studies on mice showed intravenous toxicity with acute symptoms that included convulsions, reduced motility and dyspnea. After 5% benzyl alcohol was injected in the side of a cat’s face in an alternate study, local nerve degeneration was discovered. Local anesthesia was produced at 10%.
Benzyl alcohol has a history of being toxic to children under six months old. The cause of death of 16 premature babies with low birth weights were linked to benzyl alcohol in the early 1980s. Approximately 0.9% benzyl alcohol had been used in the infants’ IV fluids as a preservative. Called gasping syndrome, symptoms encompassed bradycardia, hypotension, seizures, gasping respiration, cardiovascular collapse, hypotonia, and death.
Even earlier, benzyl alcohol had been used for many years to flush out arterial or intravenous catheters after blood samples had been taken, in order to use the same catheters for medicating or feeding a patient. Research later uncovered that the toxic effects of the solution were amplified in small infants with very small organs. Symptoms included paralysis, convulsions, hypotension and respiratory failure. Benzyl alcohol is no longer recommended for use in any infant products. For children six months or older, 5% benzyl alcohol in a solution form has been approved by the US FDA as a treatment for head lice. It specifically works in lotion shampoo with the active ingredient of 5% benzyl alcohol.
