Registration Dossier

Ecotoxicological information

Toxicity to soil microorganisms

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

The lowest unbounded NOEC of  ≥5.9 mg Se/kg dw (added concentration) was observed for the effect of selenium on nitrogen transformations 9 years after application of a sodium salt of selenium (not reported whether Na2SeO4 or Na2SeO3) to a field plot in Germany (Wilke, 1989).

Key value for chemical safety assessment

Long-term EC10 or NOEC for soil microorganisms:
5.9 mg/kg soil dw

Additional information

Two studies on the toxicity of selenium compounds to soil microorganisms were judged reliable with restriction (Klimisch 2). The reliable data cover several endpoints: N-mineralisation, nitrification, biomass, respiration and ATP-content. Only unbounded NOEC values are reported in these studies, ranging from ≥5.9 mg Se/kg dw for the effect of selenium on nitrogen transformations 9 years after application of a sodium salt of selenium (not reported whether Na2SeO4 or Na2SeO3) to a field plot in Germany (Wilke, 1989) to ≥20 mg Se/kg for the effect of Na2SeO4 on microbial biomass, respiration or ATP content in a Haplic Luvisol (Chander and Joergensen, 2007). As a conservative approach, the lowest unbounded NOEC (5.9 mg Se/kg) was selected for the effects assessment of selenite in soils. All results are based on nominal added or background corrected measured Se concentrations.