Chloroacetic Acid

Chloroacetic acid is a monohalogenated acetic acid (m-HAA) that is used as a photosensitizing agent and also in industrial synthesis of certain organic chemicals such as indigoid dyes. Chloroacetic acid is used in the topical treatment of warts in some countries and also as an herbicide and a bleaching agent for silkworm cocoons. The general population can be exposed to chloroacetic acid via ingestion of chlorinated or chloraminated drinking water. The presence of m-HAAs in drinking water is a public health concern due to their potential mutagenic and carcinogenic effects. Chloroacetic acid and volatile organochlorines are suspected to contribute to forest dieback and stratospheric ozone destruction.

The compound was first described in 1935 by Ferdinand Munz, who prepared the compound from ethylenediamine and chloroacetic acid. Today, EDTA is mainly synthesized from ethylenediamine (1, 2-diaminoethane), formaldehyde (methanal), and sodium cyanide. On direct exposure for extended time, EDTA extracts bacterial surface proteins by combining with metal ions from the cell envelope, which can eventually lead to bacterial death.
Chloroacetic acid with a short reaction time is used for the acetylation step for the residue following the incorporation of the N,N′-diisopropylethylene diamine submonomer to avoid the formation of a cyclized ketopiperazine product. Bromoacetic or chloroacetic acid acetylation can be used for the incorporation of the initial N,N′-diisopropylethylene diamine residue in the sequence.

Chloroacetic acid application is an effective alternative to cryotherapy for common and plantar warts in primary care: a randomized controlled trial.
Patients were randomly allocated to chloroacetic acid versus liquid nitrogen cryotherapy every 2 weeks for common warts (n = 188) and MCA versus cryotherapy combined with daily salicylic acid (SA) self-application for patients with plantar warts (n = 227). MCA was found to be an effective alternative to cryotherapy for both types of warts with cure rates at 13 weeks comparable in all treatment groups. In the common wart group, cure rates were 43% for MCA and 54% for cryotherapy, and in the plantar wart group, cure rates were 46% for MCA and 39% for cryotherapy combined with SA.