Arsenic acid

Long-term toxicity to fish

Description of key information

The chronic toxicity of Disodium arsenate hepathydrate to Oncorhynchus mykiss (juveniles) was studied under flowthrough conditions. Three experiments were conducted. Juveniles were continuously exposed to control, and test chemical via semi-purified test diet supplemented with DSA. The diet was supplemented with 0, 10, 50, 90, 130 or170 µgAs/g diet in experiment 1, with 0, 50 or 100 µgAs/g diet in experiment 2, and with 0, 2.5, 5, 10, 25 or 50 µgAs/g diet in experiment 3. Observations were made on the physiological, histopathological and behavioural effects. The MATC was 13 to 33 µg As/g diet. As a worst case it can be considered as a LC10.
 This study is classified as acceptable and satisfies with the guidelines requirements for an acute toxicity study with freshwater invertebrates. 
This is the most severe result of the data set. 

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

13 µg/L

Additional information

Beside the key study, another reference is available on fish long-term toxicity.

The 35d chronic toxicity of Arsenic acid to Pimephales promelas(embryos and larvae) was studied under static conditions. Embryos were continuously exposed to control, and test chemical at measured concentrations in mg a.i/L of: 0.46, 0.97, 1.9, 3.4, 6.3 and 13 mg/l. Observations were made on the survival of organisms at hatch and on the survival and growth (wet weight and total length) of larvae after 30 days (post-hatch) of exposure. The 35d-NOEC was 0.97 mg a.i/L, based on the measured concentrations.

 This study is classified as acceptable and satisfies with the guidelines requirements for an acute toxicity study with freshwater invertebrates.