Koslo, R. J., A. Butler, and V. Farina. Use of Microtox as an In Vitro Adjunct to In Vivo Dermal Irritation Testing. The Toxicologist. February 1992. 12(1): 296. (Abstract #1145).

benzethonium chloride - 121-54-0; Tween 40 - 9005-66-7; sodium dodecyl sulfate - 151-21-3; aluminum chlorohydrate - 1327-41-9

Microtox is based on the ability of test agents to interfere with metabolic processes and, therefore, light output of the bioluminescent marine bacteria, Photobacterium phosphoreum. Dose-response curves were used to calculate concentrations of test materials which caused a 50% reduction in light output (EC50). EC50 values were used to rank the dermal irritation potential of test materials. Antiperspirant salts (AlCl3), zirconium aluminum glycinate (ZAG) and aluminum chlorohydrate (ACH), surfactants (sodium lauryl sulfate (SLS), benzethonium chloride (BC), polysorbate 40 (P40), and finished products (BMP-1430, BMP-1690, and BMP-4053) were tested. Rankings of the dermal irritation potential for ingredients within each class were consistent with historical in vivo findings (AlCl3 > ZAG > ACH; BC > or = SLS > P40). Ranking of the emulsion-type finished products was consistent with historical in vivo findings (BMP-1690 > BMP 1430). BMP-4083 was ranked as the finished product with the lowest dermal irritation potential, a finding inconsistent with in vivo data. Microtox appears to have potential use for ranking the dermal irritation potential of ingredients and finished products within a given class, but does not appear to have utility in cross-class comparison.