reaction mass of calcium bis(dihydrogenorthophosphate) and calcium hydrogenorthophosphate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2006

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
See read-across justification report under Section 13 ‘Assessment Reports’.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
In accordance with REACH Annex XI, Section 1.5, of Regulation (EC) No. 1907/2006 (REACH) the standard testing regime may be adapted in cases where a grouping or read-across approach has been applied.

The similarities may be based on:
(1) a common functional group
(2) the common precursors and/or the likelihood of common breakdown products via physical or biological processes, which result in structurally similar chemicals; or
(3) a constant pattern in the changing of the potency of the properties across the category

(1) The target substance is a reaction mass of calcium hydrogenorthophosphate and calcium bis(dihydrogenorthophosphate). The source substance of calcium hydrogenorthophosphate is therefore expected to give similar results.
(2) All members of the group will ultimately dissociate into the common breakdown products of the Ca2+ cation and the PO43-anion.
(3) Calcium orthophosphates are expected to dissociate to the ionic forms in water and therefore the toxicity results can be read across on the basis that cations are abundant in natural waters and are unlikely to contribute to toxicity.


2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
See read-across justification report under Section 13 ‘Assessment Reports’.

3. ANALOGUE APPROACH JUSTIFICATION
See read-across justification report under Section 13 ‘Assessment Reports’.

4. DATA MATRIX
See read-across justification report under Section 13 ‘Assessment Reports’.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: control and 100 mg/L. Samples were taken after 1, 24, 48, 72, and 96 hours.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Tap water was passed through a membrane filter (1 μm) to remove particulate matter and then a high-grade activated carbon filter to remove any organic contaminants. Preliminary solubility trials indicated that this test substance did not produce test solution of 100 mg/L using organic solvents such as acetone, dimethyl sulfoxide (DMSO), ethanol, and N,N-dimethylformamide (DMF). Therefore, the test solution was prepared by direct addition of the test substance to dilution water.

Test organisms (species):

Oryzias latipes

Details on test organisms:

TEST ORGANISM
- Common name: Japanese rice fish
Source: Korea Institute of Toxicology (KIT), KRICT, Deajeon, Korea
- Age at study initiation (mean and range, SD): 3-4 month
- Length at study initiation (length definition, mean, range and SD): 2.0±1.0 cm
- Weight at study initiation (mean and range, SD): 0.19 g (S.D. = 0.03 g)
- Feeding during test: none


ACCLIMATION
- Acclimation period: 7 days
- Acclimation conditions: same as in test
- Feeding frequency: not fed 24 hours prior to test

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

10-250 mg/L CaCO3

Test temperature:

23.3 ± 0.1 °C

pH:

7.18-7.97

Dissolved oxygen:

5.2-8.5 mg/L

Salinity:

<0.01 mg/L (residual chlorine)

Nominal and measured concentrations:

Nominal test substance concentration: 100 mg/L
The concentrations of the test substance were measured to be 13.0-14.2 mg/L at a nominal concentration of 100 mg/L (13.0-14.2% of nominal concentration) at 0, 48, and 96 hours.

Details on test conditions:

TEST SYSTEM
- Aeration:none
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Filtered tap water (1 µm, membrane filter), residual chlorine or organic substances were removed by filtering through an activated carbon filter.
- Chlorine: < 0.01 mg/L


OTHER TEST CONDITIONS
- Photoperiod: 16:8 h day-night regime
- Light intensity: 990-1060 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Mortality and abnormality after 1, 24, 48, 72, and 96 hours

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

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 13.5 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

> 13.5 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

There were no mortalities and adverse effects observed in any of the fish exposed to control and 13.5 mg/L treatment effect group during the test. All results were expressed in terms of the mean measured concentration.

Reported statistics and error estimates:

No statistics performed

Sublethal observations / clinical signs:

Table 1. Cumulative mortality of Oryzias latipes

Nominal concentration (mg/L)	Mean measured concentration (mg/L)	Number of organisms tested	Cumulative number of dead fish
			24-hour	48-hour	72-hour	96-hour
Control	ND	7	0	0	0	0
100	13.5	7	0	0	0	0

* ND : Not detected

Table 2. Symptoms of intoxication of the test substance to Oryzias latipes

Nominal concentration (mg/L)	Mean measured concentration (mg/L)	Symptoms of Intoxication
		24-hour	48-hour	72-hour	96-hour
Control	ND	NOR(7)	NOR(7)	NOR(7)	NOR(7)
100	13.5	NOR(7)	NOR(7)	NOR(7)	NOR(7)

* ND : Not detected

* ( ) : Number of fish

* NOR : Normal

Validity criteria fulfilled:

not specified

Conclusions:

Based on the mean measured concentration a LC50(96 h) > 13.5 mg/L (nominal: LC50(96 h) >100 mg/L) was determined.

Executive summary:

The acute toxicity of Calcium hydrogenorthophosphate to fish was investigated in a study following OECD guideline 203 (Kim et al. 2013). The test was set up as a limit test under static conditions. Fish of the species Oryzias latipes were exposed to a nominal test substance concentration of 100 mg/L. The analytical recovery rate of the test substance was 13.0-14.2% of the nominal concentration. During the test period of 96 hours mortality and abnormal behavior of the test organisms were examined after 1, 24, 48, 72, and 96 hours. Mortality or adverse effects of the test substance were not observed. Based on the mean measured concentration a LC50(96 h) > 13.5 mg/L (nominal: LC50(96 h) >100 mg/L) was determined.

Description of key information

Data on the acute toxicity of the substance itself are not available. The assessment was therefore based on studies conducted with the analogue substance calcium hydrogenorthophosphate (7757-93-9) 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 Calcium hydrogenorthophosphate to fish was investigated in a study following OECD guideline 203 (Kim et al. 2013). The test was set up as a limit test under static conditions. Fish of the species Oryzias latipes were exposed to a nominal test substance concentration of 100 mg/L. The analytical recovery rate of the test substance was 13.0-14.2% of the nominal concentration. During the test period of 96 hours mortality and abnormal behavior of the test organisms were examined after 1, 24, 48, 72, and 96 hours. Mortality or adverse effects of the test substance were not observed. Based on the mean measured concentration a LC50(96 h) > 13.5 mg/L (nominal: LC50(96 h) >100 mg/L) was determined.

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

Based on the available data the assessed substance calcium bis(dihydrogenorthophosphate) is considered not acutely toxic to fish.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

100 mg/L

Additional information

nominal LC50 >1,000 mg/L.