Phosphoric acid, mono and bis-linear butyl esters, potassium 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:

2017-07-12 - 2017-07-14

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)

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Qualifier:

according to guideline

Guideline:

other: EPA Health Effects Test Guidelines, OCSPP 850.1010

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Batch/Lot Number: 7675229
Description: White/gray solid
Purity: 100%
Expiry date: 31 August 2018

Analytical monitoring:

yes

Details on sampling:

- Concentrations: control and 100 mg/L solutions
- Sampling method: Duplicate samples taken at t=0 ad t=48h in plastic tubes.
- Sample storage conditions before analysis: Frozen and kept at approx. -20 deg C at the test facility. One set of samples sent to the test site for analysis and one set retained as back-up at the test facility.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
addition of the test item, mixed into the test medium (ISO Medium) using ultrasonic bath (5 minutes). 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
- Strain/clone: Daphnia magna
- Justification for species other than prescribed by test guideline: standard species for acute immobilisation test
- Source: István Szent University, 2100 Gödöllő, Páter Károly u. 1, Hungary
- Breeding: 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 behavior or significant decrease of population is recorded.
- Number of animals: There were 20 animals in test group and control group respectively, divided into 4 replicates (5 animals / replicate)
- Age of the animals: They were less than 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.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

The reconstituted water (ISO medium) had a total hardness of 248 mg/L (as CaCO3).

Test temperature:

20.2 – 20.6°C

pH:

7.39 – 7.62

Dissolved oxygen:

7.5 – 8.5 mg/L

Salinity:

Not reported

Conductivity:

Not reported

Nominal and measured concentrations:

Nominal: 100 mg/L
Measured: 105.3 mg/L at the start and 102.9 mg/L at the end of the experiment.
As the measured concentration deviated not more than 20 per cent from the nominal, biological results are based on the nominal concentration.

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 mL glass beakers
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates):4 (main test)
- No. of vessels per control (replicates): 4 (main test)
- 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 h light/ 8 h dark
- Light intensity: no data

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : The number of immobilised animals and the percentage of immobility were determined at 24 and 48 hours.

RANGE-FINDING STUDY
- Test concentrations: 0.1, 1, 10, 100 mg/L nominal
- Results used to determine the conditions for the definitive study:

1/10 animals immobilised in control and 0.1 mg/L solutions. 0/10 animals immobilised in 1, 10, 100 mg/L solutions.
Based on these results it was decided to perform a limit test at 100 mg/L.

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.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

No immobility was observed in any of the controls or animals tested at 100 mg/L at 24 or 48 hours.
In addition to immobility, no abnormal behaviour or appearance of test animals was detected.

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.

Validity criteria fulfilled:

yes

Remarks:

All validity criteria were within acceptable limits and therefore the study can be considered as valid.

Conclusions:

The 24h and 48h EC50 value: > 100 mg/L (nominal)
The 48h No-Observed Effect Concentration (NOEC): 100 mg/L (nominal)

Executive summary:

Acute toxicity of the test item 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 (100 mg/L) 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 105.3 mg/L at the start and 102.9 mg/L at the end of the experiment.

As the measured concentration deviated not more than 20 per cent from the nominal, biological results are based on the nominal 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 the test item were as follows:

The 24h and 48h EC50 value: > 100 mg/L (nominal)

The 48h EC100 value: > 100 mg/L (nominal)

The 48h No-Observed Effect Concentration (NOEC): 100 mg/L (nominal)

The 48h Lowest Observed Effect Concentration (LOEC): > 100 mg/L (nominal)

Description of key information

The 24h and 48h EC50 value: > 100 mg/L (nominal)

The 48h No-Observed Effect Concentration (NOEC): 100 mg/L (nominal)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

Acute toxicity of the test item 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 (100 mg/L) 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 105.3 mg/L at the start and 102.9 mg/L at the end of the experiment.

As the measured concentration deviated not more than 20 per cent from the nominal, biological results are based on the nominal 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 the test item were as follows:

The 24h and 48h EC50 value: > 100 mg/L (nominal)

The 48h EC100 value: > 100 mg/L (nominal)

The 48h No-Observed Effect Concentration (NOEC): 100 mg/L (nominal)

The 48h Lowest Observed Effect Concentration (LOEC): > 100 mg/L (nominal)