Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Relevant data for Bioaccumulation endpoints and Adsorption/Desorption endpoints are available. Stability and Biodegradation are not applicable endpoints for nickel, as reported in the 2008/2009 European Union Risk Assessment for Nickel.

Link between Transformation/dissolution data and read-across approach justification

Under environmentally relevant conditions, nickel salts readily dissociate upon dissolution in aqueous media. Dissociation is a reversible process and the proportion of dissociated salt present is dependent on the pH and composition of the solution and the metal-ligand dissociation constant of the salt.Upon dissolution and dissociation, the environmental fate and behavior the nickel ion and associated anion can be measured or estimated within the environmental compartments (water, air, sediment and soil). For metals and sparingly soluble metal compounds, the transformation/dissolution protocol (T/DP, OECD 29) is designed to determine the rate and extent to which metals and SSMCs can produce soluble available ionic and other metal-bearing species in aqueous media under a set of standard laboratory conditions representative of those generally occurring in the environment. Once determined, this information can be used to evaluate the short-term and long-term aquatic toxicity of the metal or sparingly soluble metal compound from which the soluble species came.

Physicochemical and ecotoxicological data for the nickel ion is therefore essential to understanding the environmental fate and toxicological characteristics of the nickel metal, compounds, and SSMCs. Data for the metal ions can be represented by fate and toxicity data generated with simple metal salts (e.g., chloride or nitrate salts). For example, the potential hazards associated with nickel metal can be estimated by 1) measuring the rate and extent of the release of nickel ions from nickel metal using the T/DP test; and, 2) through the evaluation of the nickel free ion tested using a soluble nickel compound (e.g., nickel chloride). Thus, data for each individual nickel compounds or SSMC and the individual metal can be used to “read-across” to characterize the hazard of another nickel compound.