Boron orthophosphate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29.09.2014 - 16.12.2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 6.25, 12.5, 25, 50, and 100 mg/L
- Sampling method: Samples were taken directly after test solution preparation and after 48 hours.
- Sample storage conditions before analysis: none, samples were analysed immediately.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Preparation of WAF according to OECD guidedance No. 23 and 29.
The test item was added to the dilution water and stirred for 24 hours at ca. 20 °C. Insoluble parts were separated from the aqueous phase by filtration (0.22 μm PES membrane). The obtained solution was used as the highest test concentration. All other test concentrations were obtained by dilution of the highest test concentration.The test solutions were freshly prepared before test start.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain: Clone V
- Source: German Federal Environment Agency, Institut für Wasser-, Boden und Lufthygiene. Specimens used in the test were bred in the laboratory of the Fraunhofer IME.
- Age at study initiation (mean and range, SD): 4 - 24 h
- Method of breeding: Batches of 30 - 50 specimen were held at room temperature in 1.8 L dilution water for one week and fed with a suspension of Desmodesmus subspicatus.
- Feeding during test: none

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

1.1 mmol/L

Test temperature:

19.4 – 19.9 °C

pH:

7.9 – 8.2

Dissolved oxygen:

8.2 - 8.8 mg/L

Nominal and measured concentrations:

Nominal substance concentration: 6.25, 12.5, 25, 50, and 100 mg/L
The nominal substance concentrations correspond to: 0.64, 1.27, 2.55, 5.10, and 10.19 mg boron/L
The mean measured boron concentrations: 0.014, 0.027, 0.043 0.079 and 0.135 mg/L (between 1.3 and 2.2 % of nominal loading)

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beakers, covered with glass planes
- Material, size, fill volume: glass, 50 mL nominal volume, 50 mL fill volume
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: purified drinking water
- Alkalinity: 2.2 mmol/L
- Conductivity: 235 μS/cm

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16:8 h day-night regime
- Light intensity: 810 – 918 lx

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

TEST CONCENTRATIONS
- Range finding study:
- Results used to determine the conditions for the definitive study: No effects up to 100 mg/L (non-GLP)

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 0.135 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: mg boron/L

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 0.135 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: mg boron/L

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.135 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: mg boron/L

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: no
- Mortality of control: no
- Other adverse effects control: no

Results with reference substance (positive control):

Test with the reference substance were conducted in regular intervalls.
The latest test resulted in a 24 h EC50 value of 1.35 mg/L (95% CL: 1.20 – 1.53 mg/L)

Reported statistics and error estimates:

Statistical calculations were performed using the computer programme ToxRat®

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

09 Mar - 11 Mar 1999

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Only short abstract available

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Analytical monitoring:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Stock solution was prepared with 10000 g test substance per litre dilution water, which was also used for test solutions.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Source: Dr. Knie LWA
- Age at study initiation (mean and range, SD): 6 - 24 h
- Method of breeding: In drink water at room temperature (20 ± 1°C) with diffuse light (16h daily). Young daphnids were separated daily for test performance. Daphnids were fed daily with cells of Scenedesmus subspicatus.

Test type:

static

Water media type:

freshwater

Total exposure duration:

48 h

Test temperature:

21.1 - 22.0°C at 0h
20.8°C at 48 h

pH:

2.86 - 7.31 at 0h
2.67 - 7.28 at 48h

Dissolved oxygen:

7.6 - 7.9 at 0h
7.2 - 7.4 at 48h

Nominal and measured concentrations:

nominal: 100, 200, 400, 800, 1600, 3200, 6400 and 10000 mg/L

Details on test conditions:

TEST SYSTEM
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Intervals of water quality measurement: pH, temperature and dissolved oxygen were measured at the begin and end of test.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): After 24 and 48 h immobile daphnids were deteremined.

TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 10, 100, 1000 and 10000 mg/L
- Results used to determine the conditions for the definitive study: 100% immobile daphnids after 48h at 1000 and 10000 mg/L test concentration.

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

610 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

2 200 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

3 200 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

The pH of the two highest test concentrations does not remain in the range 6 -9 according to OECD 202. Nevertheless, the pH of the six other test concentrations is in this range 6 -9. Thus, these six test concentrations could be used for evaluation.

Immobile daphnids and water quality measurements

Conc. of test substance [mg/L]	Immobile daphnids [%]		Dissolved oxygen [mg/L]		Water temperature [°C]		pH
	24h	48h	24h	48h	24h	48h	24h	48h
Control	0	0	7.9	7.3	21.1	20.8	7.31	7.23
10000	100	100	7.8	7.2	22.0	20.8	2.86	2.67
6400	100	100	7.8	7.3	21.8	20.8	4.04	3.16
3200	40	100	7.7	7.3	21.8	20.8	6.03	6.01
1600	0	0	7.8	7.3	21.8	20.8	6.56	6.80
800	0	0	7.7	7.4	21.9	20.8	6.79	7.22
400	0	0	7.6	7.3	21.2	20.8	6.92	7.28
200	0	0	7.8	7.3	21.3	20.8	6.94	7.23
100	0	0	7.7	7.3	21.2	20.8	6.81	7.16

 

Additional information

The influence of Boron orthophosphate (CAS 13308-51-5) on immobilization of daphnids of the species Daphnia magna was investigated in a static OECD 202 test under GLP conditions. For this, the daphnids were placed in water containing the test item in a series of concentrations. Effects on immobilization were determined after 24 and 48 hours. Samples of fresh and aged test solutions were measured for test item concentrations. Considering of low water solubility, the highest nominal test substance concentration was prepared following the Water Accommodated Faction (WAF) approach according to the OECD guidance documents No. 23 and 29 to obtain the maximal solubility of the test item under the test conditions. The daphnids were exposed to a series of dilutions obtained from a filtrated eluate of a 100 mg/L loading. For the determination of daphnid immobilization four replicates of the control (test medium only) and four replicates of each test concentration were exposed to theoretical loadings of:

Nominal test item loadings: Control, 6.25, 12.5, 25, 50 and 100 mg/L, equivalent to

Nominal boron loading Control, 0.64, 1.27, 2.55, 5.10 and 10.19 mg B/L

 

The concentrations of boron in the test media were determined in the aqueous phase at the start and at the end of the test using ICP-OES (LOQ 0.58 μg B/L). At test start, the measured boron concentrations were between 1.3 and 1.6 % of nominal loading. The boron concentrations maintained stable at all test substance concentrations throughout the test period (1.4 – 2.8 % at test end). , The test evaluation was based on the nominal test substance concentration and the mean measured concentrations. The mean measured boron concentrations were 0.014, 0.027, 0.043, 0.079 and 0.135 mg/L (between 1.3 and 2.2 % of nominal loading). There were no concentration-dependent effects on immobilization up to the highest test concentrations of 0.135 mg boron per liter. The EC50 value for immobilization was set to be higher than the highest test concentration of 0.135 mg boron per liter (> 100 mg/L test item nominal).

 

A second study according to OECD 202 without GLP (Institute Fresenius, 1999) showed an EC50 (48h) of 2200 mg/L without analytical verification and no toxicity up to a nominal concentration of 610 mg/L.