Methacrylic Acid

What Is It?

Methacrylic Acid is a colorless liquid substance. In cosmetics and personal care products, Methacrylic Acid is used as an adhesion promoter (primer) in certain artificial nail products.

Why Is It Used?

Methacrylic Acid is an adhesion promoter applied to the natural nail as part of the process for application of some artificial fingernail products.

Scientific Facts

Methacrylic acid occurs in oil from the plant, Roman chamomile. Methacrylic Acid is an olefinic carboxylic acid.

Safety Information

The safety of Methacrylic Acid has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel. The CIR Expert Panel evaluated the scientific data and concluded that Methacrylic Acid was safe as used as an artificial nail primer by trained professionals, but the data were insufficient to assess the safety of retail use by consumers.

CIR Safety Review: Methacrylic Acid was readily absorbed through mucous membranes of the lungs, the gastrointestinal tract, and the skin, and is distributed to all major tissues. Undiluted Methacrylic Acid was corrosive to the skin. In three studies, no skin sensitization was observed. Methacrylic Acid was not a reproductive or developmental toxicant in laboratory tests. Case reports involving Methacrylic Acid often sometimes involve children. Effects from ingestion include drooling, gagging and vomiting.

Children exposed to undiluted Methacrylic Acid as a result of accidental spills had first and second degree burns to the eyes, face, hands, arms and chest. The Consumer Product Safety Commission (CPSC) has required child-resistant packaging for liquid household products containing more than 5% Methacrylic Acid (weight-to-volume) in a single package. A primary concern about the use of Methacrylic Acid, an extremely corrosive chemical, as a cosmetic ingredient related to whether products containing Methacrylic Acid could be safely applied to the natural nail without exposing the soft tissue surrounding the nail plate.

A videotape presented to the CIR Expert Panel demonstrated that a trained professional could use a small applicator brush to dab a limited volume of Methacrylic Acid only to the center of the nail plate, allowing the mobile liquid to spread across the nail plate without causing any exposure to the skin. There were no available data presented to demonstrate that an individual consumer could apply Methacrylic Acid and avoid inadvertent skin contact. In order to minimize any exposure, the CIR Expert Panel concluded that nail primers containing Methacrylic Acid could be used safely by trained individuals specifically instructed to ensure that there was no contact with the skin. The CIR Expert Panel expressed concern about potential inhalation exposure of nail technicians to Methacrylic Acid.

The CIR Expert Panel concluded that the current National Institute for Occupational Safety and Health (NIOSH) recommended exposure limit of 20 ppm would provide adequate protection. In addition, information was presented that indicated Methacrylic Acid product containers were very small, usually one half ounce or less with small openings in the container making excessive inhalation exposure unlikely.

Methacrylic Acid may be used in cosmetics and personal care products marketed in Europe according to the general provisions of the Cosmetics Regulation of the European Union.

Link to the EU Cosmetic Regulation:…

In Canada, products containing more than 5% Methacrylic Acid must carry the following statement: “This product contains Methacrylic Acid, is poisonous, is to be kept ourt of reach of children and, in the case of accidently ingestion, a Poison Centre or physician is to be contacted immediately.”

Link to the Health Canada website:…

More Scientific Information

Other technical names for Methacrylic Acid are: 2-methylacrylic acid, 2-methylpropenoic acid, alpha-methacrylic acid and 2-methylene propionic acid. The methyl ester of Methacrylic Acid polymerizes to form a clear plastic.