Tiered guidance for risk-informed environmental health and safety testing of nanotechnologies

Assessing nanomaterial exposures in aquatic ecotoxicological testing: Framework and case studies based on dispersion and dissolution

“…Their properties, characteristics and behaviors present significant challenges at all levels of environmental health and safety, including regulation, risk management, exposure and hazard assessment; these challenges exist in part because current standards for dissolved chemicals are not directly applicable or prescribed for testing particles or colloids (Petersen et al, 2015). Formal, internationally recognized ENM-specific guidance has yet to be developed, resulting in inconsistent testing, interpretation and decisions regarding the material physical -chemical information to be provided in dossiers submitted to regulatory agencies (Collier et al, 2015;Hund-Rinke et al, 2016;Petersen et al, 2015;Potthoff et al, 2015).…”

“…within a single ENM composition type limits the direct application of currently available, material-specific information for general risk assessment. This is further exacerbated by changes to primary ENM properties, fate and hazard due to aging and transformation in media Lowry et al, 2012), and transformation of particles from product matrices during environmental release triggers (weathering, abrasion) and processes (Collier et al, 2015). Given the variations in form, function and application, the ability to generalize the hazard, exposure and risk of an ENM (or NEP) is so far limited.…”

“…To meet the aforementioned needs, we previously published a tiered-testing strategy for characterizing the release potential, exposure and hazard of ENMs and NEPs (Collier et al, 2015). The development of that strategy and the content of this paper was based on the literature describing the novel behaviors of ENMs (relative to soluble chemicals) and the difficulties in testing them (Petersen et al, 2015).…”

“…Due to complexities in contaminant interactions and bioavailability, assessment of dredged materials necessitates the application of bioassay methods to evaluate the toxicity of suspended (and potentially settling) particles and particle-associated contaminants on a case-specific basis. The tiered-testing strategy presented in Collier et al (2015) provides support for screening and categorizing NEPs (Tier 1), determining potential for ENMs to be released from NEPs (Tier 2), fate in media (Tier 3), hazard (toxicity) potential (Tier 4) and casespecific investigations (Tier 5).…”

“…This study focused on expanding the details of Tier 4 of Collier et al (2015) strategy. We demonstrated hazard testing procedures with focus on critical issues for standardized ecotoxicity testing of ENMs discussed by others (Diamond et al, 2009;Handy et al, 2012;Holden et al, 2016;Hund-Rinke et al, 2015;Klaine et al, 2008;Petersen et al, 2015;Potthoff et al, 2015).…”