Pentacalcium hydroxide tris(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: A stock solution of test substance was prepared by adding 1.0111g to the test water and fill up to the marker in 100 mL volumetric flask. 2 mL of stock solution was added in the test water and filled up to the marker in 200 mL beaker to prepare test solutions.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Age at study initiation (mean and range, SD): <24 h
- Source: Environmenal toxicity lab., Safety Assessment Center, Korea Testing and Research Institute
- Food type (breeding): unicellular green algae, Chlorella vulgaris, daily

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

224 mg/L CaCO3

Test temperature:

20.28 ± 0.2 ℃

pH:

7.8-8.14

Dissolved oxygen:

7.73-8.18 mg/L

Nominal and measured concentrations:

Nominal test concentration: 100 mg/L
The mean concentration was analyzed to be 2.75 mg/L at a nominal concentration of 100 mg/L (2.9% of nominal concentration) at 0 and 48 hours.

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

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.:

> 2.9 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

After 24 hours and 48 hours exposure, no daphnia was immobilised in 100 mg/L of test solution. No abnormal behavior and intoxication symptoms were observed in control and treatment groups during limit test.

Reported statistics and error estimates:

No statistics performed

Table 1. Cumulative immobilization data forDaphnia magna

Nominal concentration (mg/L)	Measured concentration (mg/L)	Number of daphnids tested	Cumulative immobilized Daphnia magna (%)
			24 hours	48 hours
Control	ND	30	No immobilization	No immobilization
100	2.9	30	No immobilization	No immobilization

Table 2. Symptoms on intoxication of the test substance toDaphnia magna

Nominal concentration (mg/L)	Measured concentration (mg/L)	Symptoms of intoxication
		24 hours	48 hours
Control	ND	NOR (30)	NOR (30)
100	2.9	NOR (30)	NOR (30)

ND : Not detected, ( ) : Number of Daphnia magna, NOR : Normal

Description of key information

The substance is not acutely toxic to aquatic invertebrates

Additional information

Data on the acute toxicity of pentacalcium hydroxide tris(orthophosphate) to aquatic invertebrates are not available. The assessment was therefore based on studies conducted with the analogue substance tricalcium bis(orthophosphate) (CAS 7758-87-4) as part of a read across approach, which is in accordance with Regulation (EC) No. 1907/2006, Annex XI, 1.5.

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 the assessed substance of pentacalcium hydroxide tris(orthophosphate) is considered not acutely toxic to aquatic invertebrates.