4-Chlorophenoxyacetic acid or parachlorophenoxyacetate (pCPA) is a synthetic pesticide similar to chemicals in a group of plant hormones called auxins. Used as plant growth regulator, 4-CPA is absorbed by plant via root, stem, leaf, bloom and fruit, It is used to prevent abscission of bloom and fruit, inhibit rooting of beans, promote fruit set, induce ormation of seedless fruit. Also used for ripening and fruit thinning. It performs better when used in combination with 0.1% monopotassium phosphate. It also has herbicidal effect at high dosage. Chemical formula: C₈H₇ClO₃