Dihydrogen wolframate

Endpoint summary

Description of key information

Aquatic Bioaccumulation:

No information on the bioconcentration or accumulation in aquatic organisms was found for tungstic acid. Bioconcentration is the tendency of materials to concentrate directly from water in a living organism over time. There is no testing performed according to standard methodology in the published literature regarding bioconcentration of tungsten compounds in general or tungstic acid specifically, in aquatic organisms. However, a sodium tungstate static renewal toxicity test on fish a bioconcentration factor (BCF) was calculated as the ratio of tungsten concentration in fish tissue (in mg W per kg wet or dry) to tungsten concentration in water (in mg/L). Wet weight BCF for the test substance was calculated as 0.29 +/- 0.94 L/kg. Dry weight BCF for the test substance was calculated as 1.57 +/- 0.5 L/kg. These BCFs are low, indicating little to no immediate accumulation even at toxic exposure levels.

Terrestrial Bioaccumulation:

No information on the bioconcentration or accumulation in terrestrial organisms was found for tungstic acid. There is no testing performed according to standard methodology in the published literature regarding bioconcentration of tungsten compounds in general or tungstic acid specifically, in terrestrial organisms. Relatively low bioaccumulation of tungsten is observed in sunflower leaves at soil concentrations of 3900 mg W/kg soil, with calculated concentration factors plateauing at approximately 0.05 (Johnson et al, 2009). Tungsten concentrations factors calculated for ryegrass were higher and ranged from 56.1-0.202 (Strigul et al, 2005). However, it should be noted that background levels of tungsten in the collected soils used for testing were not determined prior to testing. Tungsten concentrations measured in earthworm tissue ranged from 1.52-193.2 mg/kg wet weight in soils with tungsten concentrations of 10-10000 mg/kg soil, respectively (non-aged soil) (Strigul et al, 2005). Additionally, tungsten concentrations of 10 and 10000 mg/kg soil yielded earthworm tissue concentrations of 3.45 and 25.9 mg/kg wet weight, respectively (Strigul et al, 2005). Using these paired concentration data the BCFs for earthworms in non-aged soils ranged 0.152-0.019 and BCFs for aged soils ranged 0.345-0.00259. However, it should be noted that background levels of tungsten in the collected soils used for testing were not determined prior to testing. Tungstic acid is not expected to bioaccumulate in terrestrial organisms.