Aspects of methodology employed in the investigation of combined chemical effects on acute oral toxicity.

The evaluation of combined chemical effects should be based on the theoretical additive LD50 values which are derived from the LD25 values of the single substances rather than the 1/2 LD50 values. If the latter are used, misinterpretation of the character of the combined action (overestimation of antagonism/underestimation of potentiation) are not excluded, particularly in case of low slope functions.

[Acute toxicity of mercurial seed-dressing agents for rats and Japanese quail with special reference to coergistic effects]. / Zur akuten Toxizität quecksilberhaltiger Saatgutbeizmittel bei Ratten und Japanwachteln unter Berücksichtigung koergistischer Effekte.

Acute oral toxicity to rat of phenyl-mercury acetate (with 44 mg/kg on males and between 54 mg/kg and 77 mg/kg on females several tests) was found to be almost identical with that of methyl-mercury toluenesulphamide (59 mg/kg on males, 54 mg/kg on females). Japanese quail, on the other hand, proved to much more sensitive to the methyl compounds, the significant difference being 25 mg/kg of methyl-mercury toluenesulphamide against 71 kg/kg of phenyl-mercury acetate. Coergistic action of combinations of phenyl-mercury acetate with HCB, Lindan, and Carboxin on female rats generally was poor. No deviation was established from additive action by a recently proposed method of evaluation. Conventional evaluation by means of an association factor (V) gave an antagonistic effect for the combination with Lindan (V = 0.54) and a potentiative effect for the combination with Carboxin (V = 1.70).