Cobalt

Long-term toxicity to fish

Description of key information

Relevant and reliable data that could be used for PNEC derivation for long-term toxicity for freshwater fish  were retrieved for 3 different species. The EC10s ranged from 351.4 µg Co/L for Pimephales promelas to 2,171 µg Co/L for the Oncorhynchus mykiss. Relevant and reliable data that could be used for PNEC derivation for long-term toxicity for marine fish were retrieved for one species. The EC10 value for the sheepshead minnow, Cyprinodon variegatus was 31,802 µg Co/L . Test results were obtained in experiments that followed international accepted guidance and were based on measured levels of dissolved cobalt as cobalt dichloride. 








Relevant and reliable data that could be used for classification for long-term toxicity for freshwater fish were retrieved for 3 different species. The lowest NOEC/EC10 values for each species ranged from 350mg Co/L for Pimephales promelas that was derived from a long-term > 28 day test, to 2100mg/L for Oncorhynchus mykiss. Test results were obtained in experiments that followed international accepted guidance and were based on measured levels of dissolved cobalt as cobalt dichloride. Chronic toxicity values are reported for one marine fish species. The EC10 value for sheepshead minnow,Cyprinodon variegatuswas 31,802mg Co/L.









 Relevant and reliable data that could be used for classification for long-term toxicity for freshwater fish were retrieved for 3 different species. The lowest NOEC/EC10 values for each species ranged from 350mg Co/L for Pimephales promelas that was derived from a long-term > 28 day test, to 2100mg/L for Oncorhynchus mykiss. Test results were obtained in experiments that followed international accepted guidance and were based on measured levels of dissolved cobalt as cobalt dichloride. Chronic toxicity values are reported for one marine fish species. The EC10 value for sheepshead minnow,Cyprinodon variegatuswas 31,802mg Co/L. Relevant and reliable data that could be used for classification for long-term toxicity for freshwater fish were retrieved for 3 different species. The lowest NOEC/EC10 values for each species ranged from 350mg Co/L for Pimephales promelas that was derived from a long-term > 28 day test, to 2100mg/L for Oncorhynchus mykiss. Test results were obtained in experiments that followed international accepted guidance and were based on measured levels of dissolved cobalt as cobalt dichloride. Chronic toxicity values are reported for one marine fish species. The EC10 value for sheepshead minnow,Cyprinodon variegatuswas 31,802mg Co/L.






  
  
  
  
  
  
  
  
  
  
  
  
  
  

 

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

EC10

Effect concentration:

350 µg/L

Marine water fish

Marine water fish

Dose descriptor:

EC10

Effect concentration:

31 802 µg/L

Additional information

Freshwater:

High quality NOEC/L(E)C10 values for chronic toxicity to freshwater fish are based on three fish species, Pimephales promelas, Danio rerio,and Oncorhynchus mykiss. The NOEC/L(E)C10 values for fish range from 350 µg Co/L for Pimephales promelas (CDI 2009b) to 2,171 µg Co/L for the Oncorhynchus mykiss (CDI 2009c). The following table indicates those NOEC or EC10 values that have been carried forward for the HC5 and PNEC derivation:

 

NOEC or EC10 values for fish that have been carried forward for the freshwater HC5/PNEC derivation.

Key Study (freshwater fish)	Selected values for the most sensitive endpoints used for derivation of the freshwater HC5
	Species	Endpoint	Value (µg Co/L)
CDI 2009d	Danio rerio	Mortality	1,085
CDI 2009b	Pimephales promelas	Biomass	350
CDI 2009c	Oncorhynchus mykiss	Biomass	2,100

Marine:

Chronic toxicity values are reported for one marine fish species. The EC10 value for the sheepshead minnow, Cyprinodon variegatus was 31,802 µg Co/L (CDI 2010c).

 

NOEC or EC10 values for fish that have been carried forward for the marine HC5/PNEC derivation.

Key Study (marine fish)	Selected values for the most sensitive endpoints used for the derivation of the marine HC5
	Species			Endpoint	Value (µgCo/L)
CDI 2010c	Cyprinodon variegatus			Biomass	31,802

Efforts have been ongoing to characterize the influence of water quality parameters on the toxicity of cobalt to the fathead minnow, Pimephales promelas. Because water quality parameters (e.g., hardness, pH, dissolved organic carbon, etc.) have effects on the bioavailability and subsequent toxicity of metals to aquatic organisms, Biotic Ligand Models (BLMs) have been developed for certain organisms. To derive the NOEC/EC10 values required for these models, P. promelas were exposed to a series of cobalt concentrations in natural waters for seven days, starting as larval fish (<24 hours old). Testing followed standard United States Environmental Protection Agency (USEPA) short-term chronic toxicity testing methodology.