Biological effects of surfactants, IV. Effects of non-ionics and amphoterics on HeLa cells.

Surfactants, representing 3 non-ionic and 1 amphoteric series of homologs exhibited marked differences in their lethal and non-toxic effects on HeLa cells. Toxicity of non-ionics generally decreased inversely with increasing hydrophilic chain length and increased with increasing size of the lipophile. Lethal levels of the surfactants coincided with surface tension reduction of the media to 45 dynes cm-1 or below. Surface tensions of non-toxic concentrations were substantially higher than those for toxic levels. Non-toxic doses were, therefore, below the critical micelle concentration of the surfactants evaluated. The data suggest that physical properties are a principal cause of the toxic effects of these detergents on HeLa cells.