What Is Acrylic Acid?

Acrylic acid(CAS number: 79-10-7),with the formula CH2CHCO2H, is an organic compound consisting of a vinyl group connected directly to a carboxylic acid terminus. This colorless liquid has a characteristic acrid or tart smell. It is miscible with water, alcohols, ethers, and chloroform. More than one billion kilograms are produced annually.

Acrylic Acid has been in production for over 30 years. It is produced in very large amounts (1.1 billion pounds in 1991) by four companies in the United States. The compound is produced naturally by several different types of algae. In 2008 there were 141 releases of acrylic acid into the atmosphere or environment by manufacturing plants. US demand for the chemical is increasing at a rate of 4 to 5 percent per year. The largest users are companies that make acrylic esters and resins, chemicals added to protective surface coatings and adhesives.

The acid undergoes the typical reactions of a carboxylic acid and, when reacted with an alcohol, it will form the corresponding ester. The esters and salts of the acid are collectively known as acrylates (or propenoates). The most common alkyl esters of the acid are methyl-, butyl-, ethyl-, and 2-ethylhexyl-acrylate.

Acrylic acid and its esters readily combine with themselves (to form polyacrylic acid) or other monomers (e.g. acrylamides, acrylonitrile, vinyl, styrene, and butadiene) by reacting at their double bond, forming homopolymers or copolymers which are used in the manufacture of various plastics, coatings, adhesives, elastomers, as well as floor polishes, and paints. The fastest growing use is in the production of superabsorbent Polyacrylic Acid polymers. Companies also use it to make oil treatment chemicals, detergent intermediates, and water treatment chemicals.

Acrylic acid is listed as a known human respiratory toxicant by the US Environmental Protection Agency.

The International Agency for Research on Cancer states it is embryotoxic and teratogenic, having the ability to adversely affect the growth or development of the embryo. However the US Environmental Protection Agency and other agencies state that no information is available to substantiate these conclusions. Tests done on rats found acrylic acid to be both embryotoxic and teratogenic.

Exposure can occur through inhalation, ingestion, and contact to the eyes and skin. Studies show that eye or skin irritation from exposure can range in intensity from mild to severe. People can be exposed to it through direct contact with a product containing it or by inhaling it in air contaminated by a nearby plant manufacturing acrylic acid.