0ba0c9c5_t_Red_104___Environment_Canada_Summary_table_Response
[Topic] Validity of evidence [Comment] The screening assessment does not provide experimental data to support the following claims: 1. That both pigments have low water solubility but there will be dissolution and dissociation of the pigments into the moieties – Pb2+ and CrO42- with the lead sulphate portion having greater solubility than the lead chromate portion. 2. Encapsulation with amorphorous silica will further decrease the solubility of these pigments therefore reducing the bioavailability of the moieties in water, sediments and soil. [Response] 
The screening assessments contains data that support these two claims: 1. The experimental solubilities of both pigments and their constituents are available in Table 2. 2. Although experimental data regarding the solubility of silica encapsulated pigments are not available, information indicative of reduced bioavailability of silica encapsulated pigments is available from experimental animal data cited in the screening assessment (Clapp et al. 1991; Pier et al. 1991). This information coupled with professional judgement lead to the statement that encapsulation with amorphorous silica will further decrease the solubility of these pigments. It should be noted that the ecological assessment of effects to aquatic organisms considered the acute effects to aquatic organisms due to the presence of both metals in solutions assumed saturated.
Public comments for C.I. Pigment Red 104 - Environment Canada