Ethyl lactate is an environmentally benign solvent with effectiveness comparable to petroleum-based solvents. It is formed by the esterification reaction of ethanol and lactic acid, which can be generated from biomass raw materials through fermentation.

Applications

Lactic acid itself is a very important chemical with applications in the food, pharmaceutical and cosmetic industries. It is also used as a monomer for the manufacture of biodegradable polymers, as substitutes for traditional petrochemical polymers.

Ethyl lactate is metabolized to ethanol and lactic acid by bacterial lipases in hair follicles and sebaceous glands. Ethanol solubilizes lipids and lactic acid and lowers the skin pH, resulting in a bactericidal effect.

Production

Lactic acid has been produced through both chemical synthesis or fermentation routes. This last pro cess is the most common, however, lactic acid derived from fermentation broths requires extensive purification processes that should be inexpensive and environmentally friendly. Ethyl lactate hydrolysis is oneofthemethodsusedtoobtainpurelactic acid.¹

Toxicity

Ethyl lactate is a central nervous system depressant and lethal to animals in high concentration (actual levels not stated) causing respiratory paralysis. Ethyl lactate is irritating in a rabbit eye and guinea pig skin. Ethyl lactate is moderately toxic. The probable oral lethal dose (human) 0.5-5 g/kg, is between 1 ounce and 1 pint or 1 pound for a 70 kg person.

References

1.Pereira CS, Viviana MT, Silva AE. Ethyl lactate as a solvent: Properties, applications and production processes – a review. Green Chemistry. 2011; 10: 2658–2671.