Peer reviewers confirm EPA has failed to show Pigment Violet 29 doesn’t present unreasonable risk

Richard Denison, a Lead Senior Scientist.

Late on Friday, EPA quietly posted the final peer review report of the Scientific Advisory Committee on Chemicals (SACC) for pigment violet 29, the first chemical for which EPA issued a draft risk evaluation under the Toxic Substances Control Act (TSCA) as amended in 2016.

No wonder EPA posted it late Friday with no announcement.  The peer reviewers’ report confirms what EDF and others have been saying since release of the draft:  EPA has fallen far short of supporting its sweeping conclusion that the chemical does not present unreasonable risk, including to vulnerable subpopulations.  The report also faults EPA’s use of systematic review, and reiterates that EPA needs to submit its method to the National Academy of Sciences for review. 

While heavy in scientist-speak in places, the report leaves no doubt about its overall conclusion.  On page 19, it states:

The Committee members were in general agreement that the information presented to support the conclusions outlined in the draft risk characterization was not sufficiently robust for this purpose.

The Committee reiterated the data deficiencies that weaken these conclusions, including: 1) inconsistencies in the available physical-chemical properties data and/or lack of high-quality solubility studies in water and octanol, or equivalent tools needed to produce estimates of solubility with sufficiently high confidence to justify their use in establishing exposure potential, 2) lack of details on workplace air monitoring necessary to establishing workplace exposure estimates with confidence, 3) lack of confidence in the readily available animal data’s ability to establish with confidence that PV29 has low hazard via inhalation or dermal pathways, 4) poor justification of uncertainties used and no justification for not using a sub-chronic-to-chronic uncertainty factor, and 5) incomplete descriptions of the level of uncertainty in published information, assumptions used, and the impact of these uncertainties on conclusions.

Over and over again, the Committee urged EPA to obtain more data on physical-chemical properties (including water solubility), releases, exposures and hazards.  Among other things, the Committee stated “Given that no acceptable inhalation toxicity studies are available for PV29, the Committee recommended a properly designed inhalation study” (p. 19).

With respect to vulnerable subpopulations, the Committee criticized EPA for not “acknowledging in the Evaluation that there are no specific data supporting the determination of hazards or exposures to children or other susceptible populations to support weight of evidence conclusions regarding risk to these susceptible subpopulations” (p. 18).

Similarly, with respect to worker exposures, the Committee noted that EPA had not “clearly acknowledge[d] that there are few data to support a confident conclusion that workers would not be exposed, and therefore, not experience human health hazards via dermal or inhalation routes” (p. 18).

With respect to environmental exposures, the Committee “considered EPA’s characterization of Environmental Releases and Exposures (Section 3.2-3.4) as cursory and dependent upon sweeping generalizations that are often unsubstantiated” (p. 16).   Similarly, with respect to occupational exposures, environmental release characteristics, potentially exposed and susceptible subpopulations, and any conclusions regarding aggregate exposure, the Committee requested that EPA “refrain from making sweeping generalizations especially when based on limited and/or uncertain information regarding physical chemical properties or toxicological testing” (p. 16)

As to EPA’s systematic review, the Committee “encouraged the EPA to proceed with its plan to have the National Academy of Sciences (NAS) conduct a peer review of the TSCA SR protocol as soon as practical” (p. 14).  Despite a commitment by EPA Administrator Andrew Wheeler in early January that EPA would “promptly” initiate the NAS review, EPA has failed to do so.

The Committee pointed to numerous deficiencies in EPA’s systematic review; among other things, it called out that “[d]ata quality criteria are needed to assess the quality of information provided via personal communications and other channels” (p. 14).


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