Registration Dossier
Registration Dossier
Diss Factsheets
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 236-501-8 | CAS number: 13410-01-0
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data

Endpoint summary
Administrative data
Description of key information
Additional information
Added risk approach
Selenium is naturally present in all environmental compartments. The median ambient background concentrations in agricultural soil and grazing land are 0.35 and 0.40 mg Se/kg, respectively (Vercaigne et al., 2010). Background Se concentrations were only measured in a few soils used for the terrestrial ecotoxicity tests and vary between 0.23 and 1.5 mg Se/kg dw (Somogyi et al., 2007; Wilke, 1989; Cartes et al., 2005; Soltanpour and workman, 1980; Liu et al., 2016). Because these background concentrations are significant compared to the NOEC and EC10 values for effects of inorganic selenium substances (selenite or selenate) to terrestrial organisms, the added risk approach is employed as a pragmatic solution. All NOEC and EC10 values are therefore based on added selenium concentrations, without taking into account the natural background in the soil. In essence this added risk assessment approach assumes that species are fully adapted to the natural background concentration and therefore that only the anthropogenic added fraction should be regulated or controlled (Appendix R.7.13-2 of the REACH guidance on “Environmental risk assessment for metals and metal compounds”).
Summary toxicity data
The available ecotoxicity results for the effect of selenium on terrestrial organisms are all based on either Na2SeO3 or Na2SeO4. All data reported are based on nominal added or background corrected measured Se concentrations in soil. A clear difference in toxicity was observed between selenite and selenate, with selenate showing significantly higher toxicity to invertebrates (Somogyi et al. 2007 and 2012) and plants (Cartes et al., 2005; Carlson et al., 1991). This is consistent with the lower adsorption and resulting higher bioavailability of selenate in soil compared to selenite. Therefore, results for sodium selenite are used for the assessment of inorganic tetravalent Se substances and results for sodium selenate are selected for the assessment of inorganic hexavalent Se substances.
The data available do not allow conclusions on the effect of soil properties (pH, organic carbon content, etc.) on the toxicity of selenite or selenate to terrestrial organisms. Therefore, all reliable toxicity data, expressed on an added concentration basis, were grouped for either selenite or selenate. The table below presents an overview of the reliable toxicity data selected for hazard assessment of selenate to terrestrial organisms.
Reliable chronic toxicity data are available for the long-term effect of selenate on 14 terrestrial species or microbial endpoints covering the 3 trophic levels (7 terrestrial plants, 4 invertebrates and 3 microbial endpoints). When several data were available for one species, the lowest reliable NOEC value was selected for the derivation of the PNEC. Selected reliable NOEC values range between 0.39 mg added Se/kg soil dry weight for shoot yield of Medicago sativa and ≥20 mg added Se/kg dry weight for microbial respiration processes in soil.
Test organism |
Taxonomic group |
Endpoint |
Effect parameter |
Value (mg added Se/kg) |
Reference |
Eisenia fetida |
Lumbricidae (annelida) |
reproduction |
NOEC |
1.7 |
Checkai et al., 2004 |
Enchytraeus albidus |
Enchytraeidae (annelida) |
reproduction |
NOEC |
3.4 |
Somogyi et al., 2012 |
Enchytraeus crypticus |
Enchytraeidae (annelida) |
reproduction |
NOEC |
2.2 |
Checkai et al., 2004 |
Folsomia candida |
Isotomidae (arthropoda) |
reproduction |
NOEC |
2.35 |
Checkai et al., 2004 |
Beta vulgaris |
Amaranthaceae(eudicotyledon) |
shoot yield |
NOEC |
≥1.5 |
Wan et al., 1988 |
Hordeum vulgare |
Poaceae(monocotyledon) |
shoot yield |
NOEC |
≥1.5 |
Wan et al., 1988 |
Lollium perenne |
Poaceae(monocotyledon) |
yield |
NOEC |
2.0 |
Cartes et al., 2005 |
Medicago sativa |
Fabaceae(eudicotyledon) |
shoot yield |
NOEC |
0.39 |
Soltanpour and Workman, 1980 |
Prunus |
Rosaceae(eudicotyledon) |
Twig length |
NOEC |
1.0 |
Pezzarossa et al., 2009 |
Lycopersicon escultentum |
Solanaceae(eudicotyledon) |
shoot yield |
NOEC |
≥1.5 |
Wan et al., 1988 |
Triticum aestivum |
Poaceae(monocotyledon) |
shoot yield |
NOEC |
2.0 |
Lyons et al., 2005 |
Natural soil microbial community |
Bacteria |
microbial biomass |
NOEC |
4.2 |
Wilke, 1988 |
Natural soil microbial community |
Bacteria |
microbial N transformation (nitrification) |
NOEC |
≥5.9 |
Wilke, 1989 |
Natural soil microbial community |
Bacteria |
microbial C transformation (respiration) |
NOEC |
≥20 |
Chander and Joergensen, 2007 |
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
