User Guide to Thresholds and Classification - Environmental ...

244User Guide for Thresholds and Classificationsensures the classification process uses the available data to the greatest extent possible in characterisingthe hazards of the mixture without needing additional testing in animals.a. DilutionIf a mixture is diluted with a diluent that is not expected to affect the reproductive or developmentaltoxicity of other ingredients, then the new mixture may be classified as equivalent to the original mixture.b. BatchingThe reproductive or developmental toxicity potential of one production batch of a complex mixture can beassumed to be substantially equivalent to that of another production batch of the same commercialproduct produced by and under the control of the same manufacturer, unless there is reason to believethere is significant variation in composition such that the reproductive or developmental toxicity potentialof the batch has changed. If the latter occurs, a new classification is necessary.c. Substantially similar mixturesGiven:i. two mixtures: (A + B) and (C + B);ii.iii.the concentration of ingredient B, toxic to reproduction, is the same in both mixtures;the concentration of ingredient A in mixture (A + B) equals that of ingredient C in mixture (C + B);andv. data on toxicity for ingredients A and C are available and substantially equivalent; that is, they are inthe same hazard category and are not expected to affect the reproductive or developmental toxicityof ingredient B; thenif mixture (A + B) has already been classified by testing, mixture (C + B) can be assigned the samecategory.d. AerosolsA hazard classification may be assigned for reproductive or developmental toxicity for aerosol products.The classification should also take into account the propellant in the aerosol.16.3.3. Classification of mixtures when data are available for all or some ingredients of themixtureThe mixture will be classified as a reproductive or developmental toxicant when at least one ingredient hasbeen classified as a 6.8A or 6.8B reproductive or developmental toxicant and is present at or above theappropriate cut-off value or concentration limit as shown in Table 16.1 for 6.8A and 6.8B respectively.The mixture will be classified for effects on or via lactation when at least one ingredient has been classifiedfor effects on or via lactation and is present at or above the appropriate cut-off value or concentration limit asshown in Table 16.1 for the 6.8C classification for effects on or via lactation.Table 16.1: Cut-off values or concentration limits of ingredients of a mixture classified as a reproductive ordevelopmental toxicant or for reproductive or developmental effects on or via lactation that trigger classification ofthe mixturesJanuary 2012 EPA0109