Tricalcium bis(orthophosphate)

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2006

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP guideline study, data originate in part from a secondary source

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: control and 100 mg/L. Samples were taken at 0 and 48 h

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Although the quoted water solubility was 20 mg/L, the test substance is very poorly soluble in water. Preliminary solubility test also indicated that the test substance was not dissolved in organic solvents such as aceton, DMSO and ethanol. Therefore, the test concentrations were prepared by directly adding the test substance into dilution water as a concept of loading rate. 10 mg of the test substance was added in test medium and filled up to 100 mL in the 150 mL crystallizing dish to prepare the test solution of 100 mg/L and then homogenized with digital homogenizer. Only the dilution water was used for the control.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Source: The Ecotoxicology Research Team, Korea Institute of Toxicology (KIT), KRICT, Deajeon, Korea (origin: the Institute of Ecological Chemistry, GSF, Germany)
- Age at study initiation (mean and range, SD): <24 h

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

243 mg/L CaCO3

Test temperature:

20.6 ± 0.5 °C

pH:

7.77 to 7.94

Dissolved oxygen:

8.2-8.9 mg/L

Nominal and measured concentrations:

Nominal test concentration: 100 mg/L

The concentrations of calcium ion were measured to be 80.3-87.1 mg/L at control, which is attributed to calcium ion (CaCl2 · 2H2O) present in the M4 culture medium.

Details on test conditions:

TEST SYSTEM
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: M4 medium


OTHER TEST CONDITIONS
- Photoperiod: 16:8 h day-night regime
- Light intensity: 620 and 650 Lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Immobility after 0, 24 and 48 hours

TEST CONCENTRATIONS
- Range finding study
- Test concentrations: control, 0.1, 1, 10, and 100 mg/L.
- Results used to determine the conditions for the definitive study: No immobility was observed at 100 mg/L

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 5.35 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

No immobilisation and adverse effects were observed in control and 100 mg/L for 48 hours. All results were expressed in terms of nominal concentration.

Reported statistics and error estimates:

No statistics performed

Description of key information

Tricalcium bis(orthophosphate) is not acutely toxic to aquatic invertebrates.

Additional information

The acute toxicity of tricalcium bis(orthophosphate) to aquatic invertebrates was investigated in a study following OECD guideline 202 (Kim et al. 2013). The study was conducted as a limit test under static conditions. Daphnia magna were exposed to a nominal test substance concentration of 100 mg/L for 48 hours. The mean measured substance concentration was 5.35 mg/L. Mortality or symptoms of intoxication were not observed. At test termination an EC50(48 h) >5.35 mg/L (nominal: EC50(48 h) >100 mg/L) based on the mean measured concentration was determined.

Comparable results were determined in studies on the toxicity of sodium and potassium phosphates to aquatic invertebrates.

Based on the available data tricalcium bis(orthophosphate) is considered not acutely toxic to aquatic invertebrates.