BREXIT: Hot topic
Worried about Brexit fallout on chemicals regulation?
Find what experts have to say on this topic. Learn how to prepare for all potential Brexit outcomes.

1.1.3.: Bridging principles for the classification of mixtures where test data are not available for the complete mixture

Where the mixture itself has not been tested to determine its hazardous properties, but there are sufficient data on similar tested mixtures and individual hazardous ingredient substances to adequately characterise the hazards of the mixture, these data shall be used in accordance with the following bridging rules referred to in Article 9(4) for each individual hazard class in Part 3 and Part 4 of this Annex, subject to any specific provisions for mixtures in each hazard class.
1.1.3.1. Dilution

►M2  If a tested mixture  ◄ is diluted with a substance (diluent) which has an equivalent or lower hazard category classification than the least hazardous original ingredient substance and which is not expected to affect the hazard classification of other ingredient substances, then one of the following shall be applied:

the new mixture shall be classified as equivalent to the original mixture;
the method explained in each section of Part 3 and in Part 4 for classification of mixtures when data are available for all components or only some components of the mixture;
in the case of acute toxicity, the method for classification of mixtures based on ingredients of the mixture (additivity formula).
1.1.3.2. Batching
The hazard category of a tested production batch of a mixture can be assumed to be substantially equivalent to that of another untested production batch of the same commercial product, when produced by or under the control of the same supplier, unless there is reason to believe there is significant variation such that the hazard classification of the untested batch has changed. If the latter occurs, a new evaluation is necessary.
1.1.3.3. Concentration of highly hazardous mixtures
In the case of the classification of mixtures covered by sections 3.1, 3.2, 3.3, 3.8, 3.9, 3.10 and 4.1, if a tested mixture is classified in the highest hazard category or sub-category, and the concentration of the components of the tested mixture that are in that category or sub-category is increased, the resulting untested mixture shall be classified in that category or sub-category without additional testing.
1.1.3.4. Interpolation within one hazard category
In the case of the classification of mixtures covered by sections 3.1, 3.2, 3.3, 3.8, 3.9, 3.10 and 4.1, for three mixtures (A, B and C) with identical components, where mixtures A and B have been tested and are in the same hazard category, and where untested mixture C has the same hazardous components as mixture A and B but has concentrations of those hazardous components intermediate to the concentrations in mixtures A and B, then mixture C is assumed to be in the same hazard category as A and B.
1.1.3.5. Substantially similar mixtures
Given the following:
(a) two mixtures each containing two ingredients:
(i) A + B
(ii) C + B;
(b) the concentration of ingredient B is essentially the same in both mixtures;
(c) the concentration of ingredient A in mixture (i) equals that of ingredient C in mixture (ii);
(d) hazard data for A and C are available and substantially equivalent, i.e. they are in the same hazard category and are not expected to affect the hazard classification of B.
If mixture (i) or (ii) is already classified based on test data, then the other mixture shall be assigned the same hazard category.
1.1.3.6. Review of classification where the composition of a mixture has changed
The following variations in initial concentration are defined for the application of Article 15(2)(a):


Table 1.2

Bridging Principle for changes in the composition of a mixture

Initial concentration range of the constituent

Permitted variation in initial concentration of the constituent

≤ 2,5 %

± 30 %

2,5 < C ≤ 10 %

± 20 %

10 < C ≤ 25 %

± 10 %

25 < C ≤ 100 %

± 5 %

1.1.3.7. Aerosols
In the case of the classification of mixtures covered by sections 3.1, 3.2, 3.3, 3.4, 3.8 and 3.9, an aerosol form of a mixture shall be classified in the same hazard category as the non-aerosolised form of the mixture, provided that the added propellant does not affect the hazardous properties of the mixture upon spraying and scientific evidence is available demonstrating that the aerosolised form is not more hazardous than the nonaerosolised form.