Sodium bromide

Toxicity to aquatic algae and cyanobacteria

Description of key information

Key study: Test method according the Dutch Standarization Organization Guideline (1980; NEN 6506: Determination of toxicity with unicellular algae). Test method equivalent or similar to OECD Guideline 201. After 72 h of exposure, the EC50 and NOEC values, based on biomass, were determined to be 8.5 g Br-/L (10.9 g NaBr/L) and 2.5 g Br-/L (3.22 g NaBr/L), respectively. 
Key study: Test method according the test procedure DIN 38 412, Part 9 (draft standard): Test Methods using Water Organisms. Test method equivalent or similar to OECD Gudeline 201. The 72h-EC50 based on algae growth rate was determined to be 20 g/L. The 72h-EC50 based on biomass was determined to be 8 g/L.
Supporting study: No guideline followed. No analytical monitoring of the test substance was made. The 96h-NOEC based on biomass was determined to be 3.2 g/L.

Key value for chemical safety assessment

EC50 for freshwater algae:

8 g/L

EC10 or NOEC for freshwater algae:

3.2 g/L

Additional information

Key study: An algae toxicity study was performed with the test substance sodium bromide using the freshwater alga Scenedesmus pannonicus. The test duration was 96 hours and the study was performed according to the Dutch Standardization Organization Guideline (1980, NEN 6506: Determination of toxicity with unicellular algae) and following a method equivalent or similar to OECD Guideline 201. The test substance's influence on algal growth, based on biomass determination, was assessed after 72 and 96 h of exposure. The 72 -h EC50 and NOEC values were determined to be 8.5 g Br^-/L (10.9 g NaBr/L) and 2.5 g Br^-/L (3.22 g NaBr/L), respectively. After 96 hours of exposure, the EC50 and NOEC values were stated to be 10 g Br^-/L (12.8 g NaBr/L) and 2.5 g Br^-/L (3.22 g NaBr/L), respectively.

Key study: A Scenedesmus cell multiplication inhibition test was performed with the test substance sodium bromide in accordance with the test procedure DIN 38 412, Part 9 (draft standard) and following a method equivalent or similar to OECD Guideline 201. The green algae Scenedesmus subspicatus was exposed to concentrations of the test substance ranging from 156 to 20,000 mg/L for up to 96 hours. The test organisms were observed for biomass and growth rate effects and measurements were made at the beginning of the test and after 24, 48, 72 and 96 hours. The 72h-EC50 based on algae (Scenedesmus subspicatus) growth rate was determined to be 20 g/L. The 72h-EC50 based on biomass was determined to be 8 g/L.

Supporting study: The effect of sodium bromide on algal growth was assessed using the freshwater alga Scenedesmus pannonicus. The test organisms were exposed to test item concentrations over an exposure period of 96 hours. Growth inhibition was assessed from the algal biomass determination. The 96h-NOEC value was determined to be 3.2 g/L.