Safening agent to protect crops from herbicidal injury. Prepn: A. Hubele, EP 94349; idem, US 4902340 (1983, 1990 both to Ciba-Geigy). Description: J. Amrein et al., Brighton Crop Prot. Conf. - Weeds 1989, 71-76. Effects on herbicide metabolism in cereals: K. Kreuz et al., Z. Naturforsch. 46C, 901 (1991).