Phosphoric acid, mono- and di-C12-18-(even numbered)-alkyl esters, sodium salts

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:

From December 16, 2016 to March 15, 2017

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)

Deviations:

yes

Remarks:

but the study integrity was not adversely affected by these deviations

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Remarks:

but the study integrity was not adversely affected by these deviations

GLP compliance:

yes

Specific details on test material used for the study:

- Name of test material (as cited in study report): Phosphoric acid, mono- and di-C 12 -18-(even numbered)-alkyl esters, sodium salts
- Appearance: white solid
- Batch no.: SEALS: 2011-104-06-01
- Purity/composition: 96.75%

Analytical monitoring:

yes

Remarks:

TOC content measurement

Details on sampling:

- Samples for TOC concentrations were taken at the start and after 48 hours of exposure. The TOC analysis performed on samples taken from 10, 18, 32, 56 and 100% of the SS should be regarded as indicative because of the low carbon concentrations. Effect parameters were based on the percentages of the saturated solution prepared at a loading rate of 100 mg/L.
- Details:
Samples for possible analysis were taken from the control and all test concentrations. In addition, the filter used to prepare the SS was retained in a freezer (≤ -15°C) for possible analysis of the residue.
Frequency at t=0 h and t=48 h
Volume 40 mL
Storage Samples were stored in a refrigerator (2-8°C) until analysis.
At the end of the exposure period, the replicates were pooled at each concentration before sampling.
Additionally, reserve samples of 40 mL were taken from all test solutions for possible analysis. If not already used, these samples were stored in a refrigerator (2-8°C) for a maximum of three months.

Vehicle:

no

Details on test solutions:

A final test was performed based on the results of a preceding combined limit/range-finding test. A Saturated Solution (SS) was prepared at a loading rate of 100 mg/L and used as the highest concentration. Lower concentrations were prepared by diluting the highest concentration in test medium.

Test organisms (species):

Daphnia magna

Details on test organisms:

Species: Daphnia magna (Crustacea, Cladocera) (Straus, 1820), at least third generation, obtained by a cyclical parthenogenesis under specified breeding conditions
Source: In-house laboratory culture with a known history
Characteristics: For the test selection of young daphnids with an age of < 24 hours, from parental daphnids of more than two weeks old
Start of each batch: With newborn daphnids, i.e. less than 3 days old, by placing about 250 of them into 5 litres of medium in an all-glass culture vessel
Maximum age of the cultures: 4 weeks
Renewal of the cultures: After 7 days of cultivation half of the medium twice a week
Temperature of medium: 18-22°C
Feeding: Daily, a suspension of fresh water algae
Medium: M7, as prescribed by Dr. Elendt-Schneider

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

180 mg/L expressed as CaCO3

Test temperature:

18-22°C

pH:

7.7 ± 0.3.

Dissolved oxygen:

8.5 - 9.8 mg/L

Salinity:

-

Conductivity:

-

Nominal and measured concentrations:

0 (medium with treatment), 10, 18, 32, 56 and 100% of the SS (100 mg/L)

Details on test conditions:

Twenty daphnids per group (four replicates, five daphnids per replicate) were exposed to a control and to 10, 18, 32, 56 and 100% of the SS. The total exposure period was 48 hours.
Test duration: 48 hours
Test type: Static
Test vessels: 100 mL, all-glass
Medium: Adjusted ISO medium
Number of daphnids: 20 per concentration
Loading: 5 per vessel containing 80 mL of test solution
Ligh:t 16 hours photoperiod daily
Feeding: No feeding
Aeration: No aeration of the test solutions.
Introduction: of daphnids Within 35 minutes after preparation of the test solutions.

Reference substance (positive control):

yes

Remarks:

potassium dichromate (K2Cr2O7)

Key result

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

85 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: the 48h-EL50 was at 85% of a saturated solution prepared at a loading rate of 100 mg/L

Details on results:

The 48h-EL50 was at 85% of a saturated solution prepared at a loading rate of 100 mg/L (95% confidence interval between 73 and 97% of the SS).

Results with reference substance (positive control):

The 24h-EC50 was 0.64 mg/L with a 95% confidence interval between 0.56 and 0.73 mg/L.
The 48h-EC50 was 0.48 mg/L with a 95% confidence interval between 0.43 and 0.53 mg/L.

Validity criteria fulfilled:

yes

Conclusions:

Under the study conditions, the 48h-EL50 was at 85% of a saturated solution prepared at a loading rate of 100 mg/L (95% confidence interval between 73 and 97% of the SS).

Executive summary:

A study was conducted to determine the short-term toxicity of the test substance to aquatic invertebrates according to OECD Guideline 202 and EU Method C.2, in compliance with GLP. Twenty daphnids per group (four replicates, five daphnids per replicate) were exposed to a control and to 10 (medium alone), 18, 32, 56 and 100% of the saturated solution (SS) and mobility was assessed. The total exposure period was 48 hours and the experiment was realised under the static conditions. Due to the complex nature of the test substance, specific analyses proved to be difficult to obtain and, after consultation with the sponsor, it was decided to analyse the Total Organic Carbon (TOC) concentration as a surrogate measure. Samples for TOC concentrations were taken at the start and after 48 h of exposure. The TOC analysis performed on samples taken from 10, 18, 32, 56 and 100% of the SS should be regarded as indicative because of the low carbon concentrations. Effect parameters were based on the percentages of the saturated solution prepared at a loading rate of 100 mg/L. The study met the acceptability criteria prescribed by the study plan and was considered valid. Under the study conditions, the 48 h-EL50 was at 85% of a saturated solution prepared at a loading rate of 100 mg/L (95% confidence interval between 73 and 97% of the SS) (Bouwman, 2017).

Description of key information

The 48 h EL50 for the test substance to daphnia was determined to be 85 mg/L (i.e., corresponding to 85% SS, prepared at a loading rate of 100 mg/L).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

85 mg/L

Additional information

A study was conducted to determine the short-term toxicity of the test substance, mono- and di- C12 -18 PSE, Na+, to aquatic invertebrates according to OECD Guideline 202 and EU Method C.2, in compliance with GLP. Twenty daphnids per group (four replicates, five daphnids per replicate) were exposed to a control and to 10 (medium alone), 18, 32, 56 and 100% of the SS and mobility was assessed. The total exposure period was 48 hours and the experiment was realised under the static conditions. Due to the complex nature of the test substance, specific analyses proved to be difficult to obtain and, after consultation with the sponsor, it was decided to analyse the Total Organic Carbon (TOC) concentration as a surrogate measure. Samples for TOC concentrations were taken at the start and after 48 hours of exposure. The TOC analysis performed on samples taken from 10, 18, 32, 56 and 100% of the SS should be regarded as indicative because of the low carbon concentrations. Effect parameters were based on the percentages of the saturated solution prepared at a loading rate of 100 mg/L. The study met the acceptability criteria prescribed by the study plan and was considered valid. Under the conditions of the study, the 48 h-EL50 was at 85% of a saturated solution prepared at a loading rate of 100 mg/L (95% confidence interval between 73 and 97% of the SS) (Bouwman, 2017).