N-Disubstituted derivative of β-alanine, q.v. Prepd (not claimed): M. Klier et al., DE 2246433; eidem, US 4127672 (1974, 1978 both to Beiersdorf). Prepn, toxicity and insect repellency studies: M. Klier, F. Kuhlow, J. Soc. Cosmet. Chem. 27, 141 (1976). Chemical, physical and toxicological properties: WHO Interim Specification for IR 3535 (WHO/IS/TC/667/2001) 15 pp. Lab and field tests of efficacy vs mosquitoes: U. Thavara et al., J. Am. Mosq. Control Assoc. 17, 190 (2001); and comparison to other repellents: D. R. Barnard et al., J. Med. Entomol. 39, 895 (2002); M. S. Fradin, J. F. Day, N. Engl. J. Med. 347, 13 (2002). HPLC determn in topical gel formulation: S. C. Marselos, H. A. Archontaki, J. Chromatogr. A 946, 295 (2002). Assessment of efficiency of repellent formulations: R. Milutinovic et al., SOFW-J. 128, 14 (2002). Review of repellency spectrum vs target pests: F. Marchio, ibid. 122, 478-485 (1996).