Giacinto Morera

Determining Acute LD50

For purposes of classifying and assigning packing groups to mixtures possessing oral or dermal toxicity hazards according to the criteria in 49CFR 173.133(a)(1), it is necessary to determine the acute LD50 of the mixture. If a mixture contains more than one active constituent, one of the following methods may be used to determine the oral or dermal LD50 of the mixture: Obtain reliable acute oral and dermal toxicity data on the actual mixture to be transported; If reliable, accurate data is not available, classify the formulation according to the most hazardous constituent of the mixture as if that constituent were present in the same concentration as the total concentration of all active constituents; or If reliable, accurate data is not available, apply the formula: where: $\frac{C_A}{T_A}+\frac{C_B}{T_B}+\frac{C_Z}{T_Z}=\frac{100}{T_M}$ $C$= the percent concentration of constituent A, B ... Z in the mixture; $T$ = the oral LD50 values of constituent A, B ... Z; $T_M$ = the oral LD50 value of the mixture.