Phosphoric Acid, C8-12(even-numbered) linear Alkyl Esters

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:

2017-11-20 - 2018-02-07

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

13 April 2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

Commission Regulation (EU) 2017/735 of 14 February 2017

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: EPA Health Effects Test Guidelines, OCSPP 850.1010

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Batch/Lot Number: 7703200
Description: clear, pale yellow liquid
Purity: considered as 100%
Manufacture date: 04 February 2016
Expiry date: 28 February 2019
Storage condition: Controlled room temperature (15-25°C, below 70 RH%)

Analytical monitoring:

yes

Details on sampling:

Analytical measurements were performed from the control and at the applied test concentration level at the beginning and at the end of the experiment.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Because the test item is very poorly soluble in water, a test solution was prepared using a saturated solution method according to the Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures, OECD No. 23.
A saturated test item solution (nominal loading rate of 100 mg/L) was prepared by dispersing/dissolving the amount of test item into the test medium (ISO Medium) two days before the start of the study. This solution was shaken for about 24 hours at approximately 30°C and then equilibrated for about 24 hours at approximately 20°C.
The non-dissolved test material was removed by filtration through a fine (0.22 μm) filter to give the 100 mg/L nominal loading rate WAF.
As a Limit test was carried out, further dilution of stock solution was not performed.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Source: István Szent University, 2100 Gödöllő, Páter Károly u. 1, Hungary; The Daphnia are bred in Ecotoxicological Laboratory of Citoxlab Hungary Ltd. The health of the stock animals is continuously monitored by visual daily checking. Abnormal behaviour or significant decrease of population is recorded.
- Age of the animals: <24 h old at the beginning of the test

ACCLIMATION
- Acclimation period: There was no acclimatization because the water used was similar to the culture water.

Number of animals: There were 20 animals in test group and control group respectively, divided into 4 replicates (5 animals / replicate)

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

Not applicable

Hardness:

248 mg/L (as CaCO3)

Test temperature:

20.5 – 21.0°C

pH:

7.00 – 7.41

Dissolved oxygen:

6.9 – 8.5 mg/L

Salinity:

Not available

Conductivity:

Not available

Nominal and measured concentrations:

Nominal loading rate = 100 mg/L
Geometric mean measured concentration = 5.62 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beaker
- Material, size, headspace, fill volume: 50 mL; 40 mL test solution
- Aeration:
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: 8 mL test solution/animal

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted water (ISO medium, according to OECD 202) was used as dilution water for both the range finding and definitive tests. The same composition of reconstituted water was used for the tests and for breeding the test animals.

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16-hour light/8-hour dark cycle
- Light intensity: Not reported.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Immobilisation - 24 & 48 hours.

VEHICLE CONTROL PERFORMED: No.

RANGE-FINDING STUDY
- Test concentrations: 0.1, 1, 10, 100 % saturated solution
- Results used to determine the conditions for the definitive study: 0.1% - 1/10 immobilised; 1% - 0/10 immoblised; 10% - 0/10 immobilised; 100% - 1/10 immobilised.
Because toxic response was not observed during the preliminary concentration rangefinding test, a Limit Test was carried out using only one test concentration at the solubility level of the test item (nominal loading rate of 100 mg/L) and one control group in a static system.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate is tested at least twice a year to demonstrate satisfactory test conditions.

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 5.62 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

5.62 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: none observed
- Mortality of control: no mortality/immobilisation observed
- Other adverse effects control: none reported
- Abnormal responses: none reported
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: none reported
- Effect concentrations exceeding solubility of substance in test medium: yes

Results with reference substance (positive control):

The date of the last study (Study Code: 17/058-023DA) with reference item Potassium dichromate (batch no.: A0345704) is: 08 - 09 March 2017.
The 24h EC50: 0.64 mg/L, (95 % confidence limits: 0.59 – 0.68 mg/L)

Reported statistics and error estimates:

No statistical analysis was performed because of the lack of toxic effects.
The EC50, NOEC, LOEC and EC100 values were determined directly from the raw data.

No immobilised animals were recorded in the control or test item groups at 24 or 48 hours.

In addition to immobility, no abnormal behaviour or appearance of test animals was detected.

Measured test concentrations:

Control: Start - none detected; End - none detected

100% saturated solution: Start - 4.83 mg/L; End - 6.55 mg/L

Geometric mean measured concentration = 5.62 mg/L

Validity criteria fulfilled:

yes

Remarks:

There were no immobilized animal in the control group and the dissolved oxygen concentration at the end of the test in control and test vessels was more than 3 mg/L.

Conclusions:

The 24h and 48h EC50 value: > 5.62 mg/L (measured)
The 48h No-Observed Effect Concentration (NOEC): 5.62 mg/L (measured)

Executive summary:

Acute toxicity of Phosphoric acid, C8-12 (even numbered) alkyl esters on Daphnia magna was assessed in an Acute immobilisation test, over an exposure period of 48 hours in a static test system (OECD TG 202). Because no toxic response was observed during the preliminary range-finding test, a Limit Test was carried out using only one test concentration at the solubility level of the test item (100 mg/L nominal loading rate WAF) and one control group in the definitive test.

The test concentration was analytically determined at the start and at the end of the experiment. Measured concentration was 4.83 mg/L at the start and 6.55 mg/L at the end of the experiment, thus the corresponding measured geometric mean test item concentration was 5.62 mg/L. The biological results are based on the measured geometric mean test item concentration.

Twenty animals, divided into four groups (glass beaker) of five animals each were used at the test concentration and for the control.

All validity criteria were met during this study.

Under the conditions of this Daphnia magna acute immobilisation study the observed endpoints for the effect of Phosphoric acid, C8-12 (even numbered) alkyl esters were the followings:

The 24h and 48h EC50 value: > 5.62 mg/L (measured)

The 48h EC100 value: > 5.62 mg/L (measured)

The 48h No-Observed Effect Concentration (NOEC): 5.62 mg/L (measured)

The 48h Lowest Observed Effect Concentration (LOEC): > 5.62 mg/L (measured)

Description of key information

The 24h and 48h EC50 value: > 5.62 mg/L (measured)

The 48h No-Observed Effect Concentration (NOEC): 5.62 mg/L (measured)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

5.62 mg/L

Additional information

Acute toxicity of Phosphoric acid, C8-12 (even numbered) linear alkyl esters on Daphnia magna was assessed in an Acute immobilisation test, over an exposure period of 48 hours in a static test system (OECD TG 202). Because no toxic response was observed during the preliminary range-finding test, a Limit Test was carried out using only one test concentration at the solubility level of the test item (100 mg/L nominal loading rate WAF) and one control group in the definitive test.

The test concentration was analytically determined at the start and at the end of the experiment. Measured concentration was 4.83 mg/L at the start and 6.55 mg/L at the end of the experiment, thus the corresponding measured geometric mean test item concentration was 5.62 mg/L. The biological results are based on the measured geometric mean test item concentration.

Twenty animals, divided into four groups (glass beaker) of five animals each were used at the test concentration and for the control.

All validity criteria were met during this study.

Under the conditions of this Daphnia magna acute immobilisation study the observed endpoints for the effect of Phosphoric acid, C8-12 (even numbered) alkyl esters were the followings:

The 24h and 48h EC50 value: > 5.62 mg/L (measured)

The 48h EC100 value: > 5.62 mg/L (measured)

The 48h No-Observed Effect Concentration (NOEC): 5.62 mg/L (measured)

The 48h Lowest Observed Effect Concentration (LOEC): > 5.62 mg/L (measured)