Manganese oxalate

Short-term toxicity to aquatic invertebrates

Description of key information

Due to visible reaction product after addition of the test item to the test water, a dispersion of the test item with the loading rate of 100 mg/L was continuously stirred at room temperature over 3 hours. Then, the dispersion was filtered. The undiluted filtrate with the loading rate of 100 mg/L and dilutions 1:2, 1:4, 1:8 and1:16of the undiluted filtrate with the loading rate of 100 mg/L were used as test media. Additionally, a control was tested in parallel. 
The preparation of the test media was based on the OECD Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures, 2000. 
  
At the start of the test medium renewal periods, the analytically determined concentrations of Manganese oxalate dihydrate (based on manganese) in the test media (dilutions 1:4, 1:2 and the undiluted filtrate) ranged between 86 and 91% of the nominal values. Thus, the correct dosing of the test item was confirmed. At the end of the test medium renewal periods, 87 to 92% of the nominal concentrations (based on manganese) were found. 
The biological test results of the test item (based on mean measured concentrations) were as follows: 
  
 	 	 
 	 	 
– 48-hour EC50:	>90	mg/L
 	 	 
– 48-hour EC0	22	mg/L
 	 	 
– 48-hour EC100:	>90	mg/L
 	 	 
 	 	 
 	 	 
The biological test results related toManganese oxalate (correction factor: 1.252 and based on mean measured concentrations) were as follows:
 	 	 
– 48-hour EC50:	>      71.9	mg/L
 	 	 
– 48-hour EC0  	17.6	mg/L
	 	 
– 48-hour EC100:	>      71.9	mg/L