A number of surfactants, including representatives of the cationic, anionic, nonionic, and amphoteric groups, were studied for their effects on lactate dehydrogenase (LDH), protein content, and de novo synthesis, at concentrations ranging from 1 to 500 μg/d medium, in a murine epidermal cell line (HEL/30). Protein synthesis, evaluated as [3H]leucine incorporation into cell proteins, was a more sensitive endpoint of toxicity than LDH leakage or protein content. Comparative surfactant toxicity followed the general order of cationic > anionic > nonionic > amphoteric. A good rank correlation was observed between their relative toxicity produced in vitro and the eye irritation produced in vivo in the Drake test. This sensitive and reproducible in vitro method may offer a means for screening potentially imtating water-soluble chemicals such as surfactants to quantify their toxicity. © 1990 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.