Cobalt hydroxide oxide

Endpoint summary

Additional information

A robust data set is available for evaluating the toxicity of cobalt to terrestrial organisms and processes. All data met the requirements for classification as Klimisch 1 or 2 (Klimisch et al 1997). In total, 141 individual NOEC/EC10 values were compiled from the database, resulting in 14 different ‘species/process mean’ NOEC/EC10 values.

• Plants: 83 NOEC/EC10 values for monocotyledon and dicotyledon species including agricultural species belonging to 7 different species and 4 different families (Brassica napus and Raphanus sativus – family of the Brassicaceae; Lycopersicon esculentum – family of the Solanaceae; Trifolium pratense and Medicago sativa – family of the Fabaceae; Hordeum vulgare and Elymus lanceolatus– family of the Poaceae).
• Invertebrates: 30 NOEC/EC10 values; hard and soft bodied organisms with different exposure routes and feeding strategies belonging to 4 different species and 3 different families (i.e. the Eisenia andrei and Eisenia fetida belonging to the family of the Lumbricidae; Enchytraeus albidus belonging to the family of the Enchytraeidae and Folsomia candida belonging to the family of the Isotomidae).
• Microbial processes: 28 NOEC/EC10 values; 3 different endpoints representing the C- and N-cycle are available (i.e. maize induced mineralisation, glucose induced respiration, and nitrification).

The terrestrial Co-database covers ecologically relevant endpoints. The selected endpoints are all relevant for potential effects at the population level: shoot and root yield based on weigh or length for the terrestrial plants; reproduction for the invertebrates; N- and C-transformation processes for microbial biomass.

Data are either from tests focusing on sensitive life stages (e.g. root elongation) or from “chronic exposure” (e.g. growth, reproduction). What comprises “chronic exposure” depends on the exposure duration and is also a function of the life-cycle of the test organisms. The duration should therefore be related to the typical life-cycle and to the recommended exposure duration from standard ecotoxicity protocols. For plants, exposure times of 14 to 21 days following emergence are used according to the ISO 11269-2 guideline (1995) for the shoot and root yield tests. An exposure time of 4 days was used for the root elongation tests with Hordeum vulgare according to the ISO 11269-1 (1993) guideline. The exposure time for the invertebrate tests varied between 28 days for Eisenia andrei (ISO 11268 (1996)) and Folsomia candida (ISO 11267 (1999)) and 42 days for Enchytraeus albidus (OECD 220 (2004)). Exposure times for microbial tests ranged between 1 day (Substrate induced respiration) and 28 days (maize residue mineralisation).

The reliable EC10/NOEC data were extracted from tests performed in natural and artificial soils, covering a wide range of the soil characteristics in Europe (pH value, organic matter, clay and effective cation exchange capacity (eCEC). It can be concluded that the soils covered by the toxicity data for each trophic level (plants, invertebrates and micro-organisms) properly reflect the variability in physico-chemical conditions encountered in European soils.