What Is Dichloroacetic Acid?
Dichloroacetic acid, represented by the chemical formula CHCl2COOH, is a variant of acetic acid. This colorless liquid is characterized by its pungent odor, higher acidity compared to acetic acid, and deliquescent properties. It is water-soluble and miscible with acetone, ether, and ethanol.
Formed as a disinfection byproduct during water purification, it arises when organic substances, bromine, and chlorine react in raw tap water. It is regulated under various laws as a poisonous and deleterious substance and a flammable liquid.
Uses of Dichloroacetic Acid
Dichloroacetic acid serves primarily as an intermediate in organic synthesis and pharmaceuticals, leading to the production of its salts and esters, test reagents for fiber analysis, and disinfectants. Its derivatives, including sodium dichloroacetate, are explored for anticancer properties and potential therapeutic effects.
Properties of Dichloroacetic Acid
Appearing as a colorless to light reddish-brown liquid, dichloroacetic acid has a molecular weight of 128.94 and a CAS number of 79-43-6. It has a melting point of 5-6°C, a boiling point of 194°C, and a density of 1.563 g/cm3. While stable under normal conditions, exposure to light can affect its stability, leading to decomposition products like carbon monoxide, carbon dioxide, and halides.
Other Information on Dichloroacetic Acid
1. Safety
GHS classifies it as posing risks of metal corrosion, acute dermal toxicity, skin and eye damage, mutagenicity, carcinogenicity, reproductive toxicity, specific target organ toxicity, and environmental hazards. It can cause severe skin and eye irritation, genetic mutations, carcinogenic effects, and damage to fertility or unborn children. Risks include respiratory system damage and, with long-term exposure, potential harm to the central nervous system, liver, pancreas, kidneys, and male reproductive organs.
2. First Aid
In case of inhalation, move the affected person to fresh air and seek medical attention if symptoms persist. For skin contact, remove contaminated clothing and wash the area with soap and water. If ingested, rinse the mouth and seek immediate medical help, especially if the person is unconscious. Always bring the chemical’s SDS and other relevant manuals when seeking medical assistance.
3. Handling Methods
Ensure proper ventilation and local exhaust systems in indoor workspaces. Provide safety showers, and eye washing stations, and wear appropriate protective gear, including masks, gloves, and goggles. Follow proper disposal methods for contents and containers, and maintain hygiene by avoiding consumption of food or beverages and washing thoroughly after handling.
4. Storage
Store in cool, well-ventilated, light-protected, sealed areas. Use corrosion-resistant containers and keep away from incompatible materials.
5. Water Quality Standards
Tap water standards mandate a maximum dichloroacetic acid concentration of 0.03 mg/L. Given its formation during water purification, eliminating it from tap water is challenging.