3.8.3. Classification criteria for mixtures
3.8.3.1. Mixtures are classified using the same criteria as for substances, or alternatively as described below. As with substances, mixtures shall be classified for specific target organ toxicity following single exposure.
3.8.3.2. Classification of mixtures when data are available for the complete mixture
3.8.3.2.1. When reliable and good quality evidence from human experience or appropriate studies in experimental animals, as described in the criteria for substances, is available for the mixture, then the mixture shall be classified by weight of evidence evaluation of these data (see 1.1.1.4). Care shall be exercised in evaluating data on mixtures, that the dose, duration, observation or analysis, do not render the results inconclusive.
3.8.3.3. Classification of mixtures when data are not available for the complete mixture: bridging principles
3.8.3.3.1. Where the mixture itself has not been tested to determine its specific target organ toxicity, but there are sufficient data on the individual ingredients and similar tested mixtures to adequately characterise the hazards of the mixture, these data shall be used in accordance with the bridging principles set out in section 1.1.3.
3.8.3.4. Classification of mixtures when data are available for all components or only for some components of the mixture
3.8.3.4.1. Where there is no reliable evidence or test data for the specific mixture itself, and the bridging principles cannot be used to enable classification, then classification of the mixture is based on the classification of the ingredient substances. In this case, the mixture shall be classified as a specific target organ toxicant (specific organ specified), following single exposure, when at least one ingredient has been classified as a Category 1 or Category 2 specific target organ toxicant (single exposure) and is present at or above the appropriate generic concentration limit as mentioned in Table 3.8.3 for Category 1 and 2 respectively.
3.8.3.4.2. These generic concentration limits and consequent classifications shall be applied appropriately to single-dose specific target organ toxicants.
3.8.3.4.3. Mixtures shall be classified for either or both single- and repeated-dose toxicity independently.
Table 3.8.3
Generic concentration limits of ingredients of a mixture classified as a specific target organ toxicant that trigger classification of the mixture as Category 1 or 2
|
Ingredient classified as: |
Generic concentration limits triggering classification of the mixture as: |
|
|
Category 1 |
Category 2 |
|
|
Category 1 Specific Target Organ Toxicant |
Concentration ≥ 10 % |
1,0 % ≤ concentration < 10 % |
|
Category 2 Specific Target Organ Toxicant |
|
Concentration ≥ 10 % [(Note 1)] |
Note 1
If a Category 2 specific target organ toxicant is present in the mixture as an ingredient at a concentration ≥ 1,0 % a SDS shall be available for the mixture upon request.
3.8.3.4.4. Care shall be exercised when toxicants affecting more than one organ system are combined that the potentiation or synergistic interactions are considered, because certain substances can cause target organ toxicity at < 1 % concentration when other ingredients in the mixture are known to potentiate its toxic effect.
3.8.3.4.5. Care shall be exercised when extrapolating toxicity of a mixture that contains Category 3 ingredient(s). A generic concentration limit of 20 % is appropriate; however, it shall be recognised that this concentration limit may be higher or lower depending on the Category 3 ingredient(s) and that some effects such as respiratory tract irritation may not occur below a certain concentration while other effects such as narcotic effects may occur below this 20 % value. Expert judgement shall be exercised. ►M2 Respiratory tract irritation and narcotic effects are to be evaluated separately in accordance with the criteria given in section 3.8.2.2. When conducting classifications for these hazards, the contribution of each component should be considered additive, unless there is evidence that the effects are not additive. ◄
3.8.3.4.6. In cases where the additivity approach is used for Category 3 ingredients, the ‘relevant ingredients’ of a mixture are those which are present in concentrations ≥ 1 % (w/w for solids, liquids, dusts, mists, and vapours and v/v for gases), unless there is a reason to suspect that an ingredient present at a concentration < 1 % is still relevant when classifying the mixture for respiratory tract irritation or narcotic effects.