Evaluation of the in vitro genetic toxicity of 4-(2, 4-dichlorophenoxy)butyric acid.

The herbicide 4-(2,4-dichlorophenoxy)butyric acid (2,4-DB) is principally used in the USA on peanuts, soybeans and alfalfa. In Europe, it is used on undersown spring barley and grassland (with clover). The genetic toxicity in vitro of the dimethylamine salt of 2,4-DB was examined by employing a range of end points including gene mutation in bacteria (Ames test) and mammalian cell cultures (CHO/HGPRT assay), cytogenetic abnormalities in mammalian cells (CHO/chromosomal aberration assay), and induction of DNA damage and repair in rat hepatocytes.

Chronic dietary toxicity and oncogenicity evaluation of MCPA (4-chloro-2-methylphenoxyacetic acid) in rodents.

The chronic toxicity and oncogenicity of 4-chloro-2-methylphenoxyacetic acid (MCPA) were evaluated in Wistar rats at target doses of 20, 80, and 320 ppm for 2 years. Chronic effects were noted in male and/or female rats in the 80- and 320-ppm dose groups, namely elevations in triglycerides and serum glutamic transaminase levels. Nephrotoxicity was confined to male rats in the 320-ppm dose group.

Chronic dietary toxicity study on 2,4-dichlorophenoxybutyric acid in the dog.

2,4-Dichlorophenoxybutyric acid (2,4-DB) is principally used in the United States as a herbicide on peanuts, soybeans, and alfalfa. In Europe, it is used on cereals, undersown cereals, lucerne (alfalfa), clover, and clover mixtures. A 1-year chronic toxicity study in the dog was performed on 2,4-DB.

Chronic dietary toxicity/oncogenicity studies on 2,4-dichlorophenoxybutyric acid in rodents.

2,4-Dichlorophenoxybutyric acid (2,4-DB) is principally used in the United States on peanuts, soybeans, and alfalfa. In Europe, it is used on cereals, undersown cereals, lucerne (alfalfa), clover, and clover mixtures. Doses in the 2-year chronic/oncogenicity rat study were 0, 60, 600, and 1800 ppm.