Registration Dossier

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
PNEC aqua (freshwater)
PNEC value:
7.1 µg/L
Assessment factor:
1
Extrapolation method:
sensitivity distribution
PNEC freshwater (intermittent releases):
0 µg/L

Marine water

Hazard assessment conclusion:
PNEC aqua (marine water)
PNEC value:
8.6 µg/L
Assessment factor:
2
Extrapolation method:
sensitivity distribution
PNEC marine water (intermittent releases):
0 µg/L

STP

Hazard assessment conclusion:
PNEC STP
PNEC value:
0.33 mg/L
Assessment factor:
100
Extrapolation method:
assessment factor

Sediment (freshwater)

Hazard assessment conclusion:
PNEC sediment (freshwater)
PNEC value:
109 mg/kg sediment dw
Assessment factor:
1
Extrapolation method:
sensitivity distribution

Sediment (marine water)

Hazard assessment conclusion:
PNEC sediment (marine water)
PNEC value:
109 mg/kg sediment dw
Assessment factor:
1
Extrapolation method:
sensitivity distribution

Hazard for air

Air

Hazard assessment conclusion:
no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:
PNEC soil
PNEC value:
29.9 mg/kg soil dw
Assessment factor:
2
Extrapolation method:
sensitivity distribution

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
PNEC oral
PNEC value:
0.12 mg/kg food
Assessment factor:
10

Additional information

The approach for deriving PNEC values was used in the 2008/2009 European Union Existing Substances Risk Assessment of Nickel (EU RAR) (EEC 793/93). The EU RAR was jointly prepared by the Danish Environmental Protection Agency (DEPA), which served as the Rapporteur of the Existing Substances Risk Assessment of Nickel, and the Nickel Producers Environmental Research Association (NiPERA), which represented the Nickel Industry in this process. The complete Environment section of the EU RAR can be found in the pdf linked to the following URL:

 http://ecb.jrc.ec.europa.eu/DOCUMENTS/Existing-Chemicals/RISK_ASSESSMENT/REPORT/nickelreport311.pdf

 

All of the approaches described were discussed by the Technical Committee for New and Existing Substances (TC NES), and received final approval at the TC NES I meeting in April, 2008.

 

Procedure for considering new data in the nickel ERVs and PNECs used for environmental hazard

A comprehensive literature review is conducted annually using PUBMED and Web of Science scientific databases (which cover searches in TOXNET, Toxline, BIOSIS, and DART databases). “Nickel” is used as a broad search term, as well as terms from section titles in the IUCLID database template for Section 5 (Environmental Fate) and Section 6 (Ecotoxicology). The substance identifier synonyms include nickel, nickel ion, nickel (2+) and Ni2+. Study inclusion was limited to publications in English (or that have an abstract in English at a minimum).

Reliability scoring is based on the systematic approach for evaluating the quality of experimental ecotoxicological data. These criteria were developed by the Nickel Institute based on the Environment section of the European Union’s Existing Substances Risk Assessment of Nickel, which assessed the risk associated with the ongoing use of nickel metal, nickel chloride, nickel sulphate, and nickel dinitrate. The guidance used in the risk assessment was developed in parallel with the Metals Environmental Risk Assessment Guidance (MERAG), which sought to provide metal-specific risk assessment guidance as a supplement to the EU’s Technical Guidance Document (TGD) that was established mainly on principles developed for organic substances.

The assessment of data adequacy involves a review of individual data elements with respect to how the study is conducted and how the results are interpreted in order to score the study. The term “adequacy” covers both the reliability of the available data and the relevance of the data to assess the ecotoxicity of the substance.

New Environmental Fate and Ecotoxicity data are reviewed in the context of existing Ecotoxicity Reference Values (ERVs) and Predicted No-Effects Concentrations (PNECs). ERVs and PNECs were established in conjunction with the Danish Rapporteur during the Existing Substances Risk Assessment of nickel in 2008. New data are evaluated to ensure that they fit within the boundaries of the ranges for the existing ERVs and PNECs. Any newly identified data falling outside of the identified endpoint ranges are evaluated to ensure that their inclusion in the REACH dossier will not impact the existing ERVs or PNECs. A full evaluation and recalculation of the nickel ERVs will occur in 2020. An examination of the nickel PNECs is scheduled for 2021.    

Common effects assessment basis:

 The ecotoxicity databases on the effects of soluble nickel compounds to aquatic, soil- and sediment-dwelling organisms are extensive. It should be noted that the effects assessments of Nickel oxide is based on the assumption that adverse effects to aquatic, soil- and sediment-dwelling organisms are a consequence of exposure to the bioavailable Ni-ion, as opposed to the parent substances. The result of this assumption is that the ecotoxicology will be similar for all soluble Ni substances used in the ecotoxicity experiments. Therefore, data from soluble nickel substances are used in the derivation of chronic ecotoxicological NOEC and L(E)C10 values. If both NOEC and L(E)C10 data are available for a given species, the L(E)C10 value was used in the effects assessment.

Read-across justification is provided as an attachment (see Information panel)

Conclusion on classification

Ni oxide is currently classified as Aquatic Chronic 4 (H413: May cause long lasting harmful effects to aquatic life) according to the 1st ATP to the CLP Regulation. However, a recent study evaluating the transformation and dissolution of green Ni oxide using the T/D Protocol (OECD, 2001) found it to be essentially unreactive. The results of the study indicate that the net concentration change in total dissolved Ni for the seven- and 28 day test at 1 mg/L loading at pH 6 and at pH 8 was less than the pH 6 acute, pH 8 acute Ecotoxicity Reference Values (ERVs) for Ni (286 µg Ni/L at pH 6, 146 µg Ni/L at pH 8), and chronic ERVs 23 µg Ni/L at pH 6 and 6 µg Ni/L at pH 8, respectively). Specifically, dissolved Ni concentrations were 0.23 µg Ni/L and <0.1 µg Ni/L at pH 6 and pH 8, respectively. The 10 and 100 mg/L loadings for the seven-day tests at pH 6 and 8 exhibited similar sub µg/L values of total dissolved Ni, which were all below the respective ERVs. Since the total dissolved Ni concentrations for the 7-day acute tests for all loadings and the 28-day chronic test were all significantly less than the respective Ni ERVs, the green Ni oxide would not classify under the GHS. Additional testing indicated that cobalt release was three orders of magnitude lower than the cobalt ERV and therefore would not classify under the GHS.

Ni oxide is currently classified as Aquatic Chronic 4 (H413: May cause long lasting harmful effects to aquatic life) according to the 1st ATP to the CLP Regulation. A recent study evaluating the transformation and dissolution of black Ni oxide using the T/D Protocol (OECD, 2001) suggests that a more stringent classification would be appropriate. The results of the study indicate that the net concentration changes in total dissolved Ni for the seven day test at the 1 mg/L loading at pH 6 was 82.8 µg Ni/L and 11.7 µg Ni/L at pH 8. These dissolved Ni concentrations were less than the pH 6 acute and pH 8 acute Ecotoxicity Reference Values (ERVs) for Ni (286 µg Ni/L at pH 6, 146 µg Ni/L at pH 8), and chronic ERVs 23 µg Ni/L at pH 6 and 6 µg Ni/L at pH 8, respectively). Based on these results, the black Ni oxide would not classify as R50/53 (Very toxic to aquatic life with long lasting effects) or Acute I/Chronic I. The 10 mg/L loading was not tested at either pH 6 or 8, but extrapolation of the 1 mg/L loading rate results to a loading rate of 10 mg/L suggests that dissolution at 10 mg/L would exceed the acute ERVs (i.e., assuming that a 10-fold difference in dissolved Ni would accompany the difference in loading rate from 1 to 10 mg/L, dissolved Ni concentrations of approximately 830 µg Ni/L at pH 6 and 120 µg Ni/L at pH 8 would be expected). Exceedance of ERVs at the 10 mg/L loading rate would result in an appropriate classification for black Ni oxide as R51/53 (Toxic to aquatic life with long lasting effects) or Chronic II.

While no changes to the existing classification are proposed within this registration file, the results of the T/D P testing on green and black NiO can be found in Section 5.6 of IUCLID.

 

Environmental Transformation and Removal

 

The 2ndATP to the CLP introduced the chronic (long-term) environmental toxicity endpoint as defined by the 3rdversion of the UN-GHS into the EU hazard classification and labeling scheme. The GHS and EU scheme include the concept of degradation whereby rapid degradation from the water column (greater than 70 % removal in 28 days) results in different classification cut-off values and categories.  For metals and inorganic metal compounds, the rapid and irreversible removal from the water column is equated to the rapid degradation concept for organics.  The current draft guidance on metals includes a proposal to apply the “rapid degradation principle for organics” measured as a 70 % removal rate in 28 days in a comparable way for metals from laboratory and field experiments or by using a recently developed model.

 

A weight of evidence approach was developed to address the unique properties of metals in the context of hazard classification (Burton et al., 2019). This approach includes the development and application of an extension of the previously developed Transformation and Dissolution Protocol (i.e., the T/DP-E) to assess to assess the “degradability” of metals in terms of environmental transformation and removal. The weight of evidence approach also includes consideration of intrinsic properties, field data, laboratory studies (not necessarily related to the T/DP), and modeling analyses.

 

There has been considerable research on physical and chemical processes that determine the bioavailability and fate of nickel and other metals in surface water and sediment. Decades of research on metal speciation and partitioning behavior has supplied quantitative and mechanistic descriptions of their interactions with natural particles which scavenge them from the water column. The affinity of nickel and other metals for the various functional groups present on environmental particles varies in a predictable way based on their intrinsic properties. The interaction between metals such as nickel and ligands (both in solution and on the surface of particulate matter) involves breaking and making chemical bonds and has been shown to influence their bioavailability. There is an abundance of evidence to support sediment as the ultimate repository of nickel and other metals. In sediment, sulfides, iron (hydr)oxides, and manganese oxides remove nickel and other metals from pore water via precipitation and/or sorption, thereby decreasing their solubility and bioavailability.

Field investigations of nickel fate in whole-lake experiments or large-scale surveys are less prevalent than for other metals (e.g., copper). However, there is evidence in estuaries and a lake that nickel is removed from the water column. Mass balance inventories for nickel in several estuaries (Forth, Gironde, Scheldt, and the Gulf of St. Lawrence) indicate that much of it is removed from the water column and retained within the estuary itself as opposed to being transported out. Available data fromCostello et al. (2016)andTopping et al. (2001)provide insight into the behavior of nickel in sediments. Soon after its introduction into a sediment, nickel pore water concentrations and the potential for toxicity decline(Costello et al., 2016). While the nickel flux may be directed out of the sediment in some cases, it is possible that the associated impacts to the water column are not substantial nor result in concentrations above regulatory levels as was the case for the locations sampled in San Francisco Bay(Topping et al., 2001; Yee et al., 2007).

 

Laboratory and modeling studies provide additional insight into nickel removal from the water column. The simple need to replenish nickel in microcosm studies with a frequency on the time-scale of days provides evidence that removal occurs relatively rapidly. The T/DP-E experiments demonstrate that 70% removal of nickel within 28 days was achieved in many experiments where this was used as a metric for environmental transformation and removal. Substantial nickel remobilization was not observed following resuspension of settled particles in T/DP-E experiments. The rate/extent of nickel removal was influenced by the characteristics and amount of the substrate used in the laboratory tests. Assessment of nickel removal in a generalized lake using state-of-the-art chemical speciation models within the TICKET-UWM indicated that 70% removal of nickel in 28 days occurs at different water pH values and with different loadings. Furthermore, feedback from sediment did not interfere with attainment of low nickel concentrations in the water column of the model. 

 

Overall, the evidence examined in this report supports the conclusion that nickel, like many other metals, has a large affinity for particles in the natural environment and is removed to a large extent from the water column of field-scale systems such as lakes, rivers, and estuaries; laboratory-scale systems such as the T/DP-E; and model systems such as the TICKET-UWM generalized lake. Furthermore, field, laboratory, and modeling data assessed in this report do not indicate substantial impacts to the water column due to nickel remobilization from sediment.

 

For more information, see Appendix XX.