Diethyl fumarate is a decomposition product of Malathion (an insecticide). Diethyl fumarate is a reputed skin irritant. Diethyl fumarate can causes non-immunologic contact urticaria on skin[1][2].
[1]. Jr FA, et, al. Gas chromatographic determination of diethyl fumarate in malathion extracts and preparations used for control of body lice. J Econ Entomol. 1968 Apr;61(2):457-9. [2]. Lahti A, et, al. Contact urticaria from diethyl fumarate. Contact Dermatitis. 1985 Mar;12(3):139-40.
















