By D. J. Wildish
Water Research, Volume 8, Issue 7, July 1974, Pages 433-437, ISSN 0043-1354, DOI: 10.1016/0043-1354(74)90074-8.

Lethal response of Atlantic salmon parr, as 96-h LC50, is semi-logarithmically related to the number of moles of ethylene oxide in the polyoxyethylated surfactant. 96-h LC50 of polyoxyethylene (10) monolaurate = 7.5 mg l1, polyoxyethylene (10) lauryl ether = 3[middle dot]5 mg l-1, and polyoxyethylene (10) octadecyl amine = 0[middle dot]2 mg l-1.
Evidence is presented which suggests that polyoxyethylene esters with up to 18-20 moles of ethylene oxide are partially detoxified in the animal, resulting in changes in lethal response. Possible physiological explanations for the relationship between polyoxyethylene chain length and lethality involve uptake rates and attainment of a critical concentration of surfactant at the unknown active site.

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