Consumer Chemicals and Containers Regulations, 2001

Marginal note:Additivity formulas — LD₅₀ or LC₅₀ of mixtures

• 36 (1) The LD₅₀ or LC₅₀ of a mixture may be determined from the LD₅₀ or LC₅₀ of its ingredients that are present in a concentration of 1% or more, using one of the following additivity formulas, as the case may be:

  • (a) for a solid or a liquid

    LD₅₀ = 1/[(P_a/LD_50a)+(P_b/LD_50b)+...+(P_n/LD_50n)]

    where

    LD₅₀

    represents the LD₅₀ of the mixture,

    LD_50a to LD_50n

    represent the LD₅₀ of each ingredient that is present in a concentration of 1% or more, and

    P_a to P_n

    represent the proportion by weight of each ingredient that is present in a concentration of 1% or more; or

  • (b) for a gas, vapour, dust, mist or fume

    LC₅₀ = 1/[(P_a/LC_50a)+(P_b/LC_50b)+...+(P_n/LC_50n)]

    where

    LC₅₀

    represents the LC₅₀ of the mixture,

    LC_50a to LC_50n

    represent the LC₅₀ of each ingredient that is present in a concentration of 1% or more, and

    P_a to P_n

    represent the proportion by weight of each ingredient that is present in a concentration of 1% or more.

• Marginal note:Complex mixture

  (2) For the purposes of the additivity formulas set out in subsection (1), “ingredient” includes a complex mixture.

• Marginal note:When LD₅₀ or LC₅₀ of ingredient is not known but can be estimated

  (3) When the LD₅₀ or LC₅₀ of one or more ingredients present in a chemical product in a concentration of 1% or more is not known, the responsible person may, in the additivity formulas set out in subsection (1), use an estimated LD₅₀ or LC₅₀ determined in accordance with good scientific practices.

• Marginal note:When LD₅₀ or LC₅₀ of ingredient is not known and cannot be estimated

  (4) When the LD₅₀ or LC₅₀ of one or more ingredients present in a chemical product is not known and cannot be estimated from information referred to in paragraph 35(1)(b) or (c), the responsible person, in the additivity formulas set out in subsection (1), must substitute for the LD₅₀ or LC₅₀ of the ingredient, the LD₅₀ or LC₅₀ of the most toxic known ingredient that is present in the product at a concentration of 1% or more.