Registration Dossier

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Between 16 March 2010 and 26 March 2010.
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of relevant results.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Remarks:
Date of inspection: 15th September 2009. Date of signature: 26th November 2009

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Sponsor's identification :Lanolin Fatty Acids
Description : brown waxy solid
Batch number : 0000371886
Date received : 8 February 2010
Expiry date : 21 September 2010
Storage conditions :room temperature in the dark

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: Loading rate of 100 mg/l in definitive test

- Sampling method: Analysis of the WAF was carried out by Total Organic Carbon (TOC) analysis. Water samples were taken from the control (replicates R1 – R4 pooled) and the 100 mg/l loading rate WAF test group (replicates R1 - R2 and R3 - R4 pooled) at 0 and 48 hours.

- Sample storage conditions before analysis: Duplicate samples were taken and stored at approximately -20°C for further analysis if necessary.

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
Pre-study work was carried out to determine whether stirring for a prolonged period produced significantly higher levels of total organic carbon, as an indicator of soluble organic materials, in the WAF. A WAF of a nominal loading rate of 100 mg/l was prepared in duplicate in deionised reverse osmosis water and stirred using a stirring rate such that a vortex was formed to give a slight dimple at the water surface. One loading rate was stirred for a period of 23 hours and the other for a period of 95 hours. After a 1-Hour standing period the mixtures were then removed by siphon and samples taken for Total Organic Carbon analysis.

It is evident from this work that increasing the stirring period did not significantly increase the amount of carbon in the WAF and so preparation of the WAF was maintained at 24 hours.

Range-finding test
Amounts of test item (5.0, 50 and 500 mg) were separately added to the surface of 5 litres of reconstituted water to give the 1.0, 10 and 100 mg/l loading rates respectively. After the addition of the test item, the reconstituted water was stirred by magnetic stirrer using a stirring rate such that a vortex was formed to give a dimple at the water surface. The stirring was stopped after 23 hours and the mixtures allowed to stand for 1 hour. Microscopic observations made on the WAFs indicated that a significant amount of dispersed test item was present in the water column and hence it was considered justifiable to remove the WAFs by filtering through a glass wool plug (2-4 cm in length). A wide bore glass tube, covered at one end with Nescofilm was submerged into the vessel, sealed end down, to a depth of approximately 5 cm from the bottom of the vessel. A length of Tygon tubing was inserted into the glass tube and pushed through the Nescofilm seal. A glass wool plug was inserted into the opposite end of the tubing and the WAF removed by mid-depth siphoning (the first approximate 75-100 ml discarded) to give the 1.0, 10 and 100 mg/l loading rate WAFs. Microscopic observations of the WAFs were performed after filtering and showed no undissolved test item to be present.

Definitive test
Based on the results of the range-finding test a "Limit test" was conducted at a single loading rate of 100 mg/l to confirm that no immobilisation or adverse reactions to exposure were observed.

Experimental preparation
Due to the low aqueous solubility and complex nature of the test item for the purposes of the definitive test the test item was prepared as a Water Accommodated Fraction (WAF).
An amount of test item (500 mg) was added to the surface of 5 litres of reconstituted water to give the 100 mg/l loading rate. After the addition of the test item, the reconstituted water was stirred by magnetic stirrer using a stirring rate such that a vortex was formed to give a dimple at the water surface. The stirring was stopped after 23 hours and the mixture allowed to stand for 1 hour. Microscopic observations made on the WAF indicated that a significant amount of dispersed test item was present in the water column and hence it was considered justifiable to remove the WAF by filtering through a glass wool plug (2-4 cm in length). A wide bore glass tube, covered at one end with Nescofilm was submerged into the vessel, sealed end down, to a depth of approximately 5 cm from the bottom of the vessel. A length of Tygon tubing was inserted into the glass tube and pushed through the Nescofilm seal. A glass wool plug was inserted into the opposite end of the tubing and the WAF removed by mid-depth siphoning (the first approximate 75-100 ml discarded) to give the 100 mg/l loading rate WAF. Microscopic observations of the WAF were performed after filtering and showed no micro-dispersions to be present.
Total Organic Carbon (TOC) analysis was performed on the test preparations at 0 and 48 hours

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Water flea
- Strain: not applicable
- Source: In-house laboratory culture
- Age at study initiation (mean and range, SD): !st instar
- Weight at study initiation (mean and range, SD): not determined
- Length at study initiation (length definition, mean, range and SD): not determined
- Valve height at study initiation, for shell deposition study (mean and range, SD): not applicable
- Peripheral shell growth removed prior to test initiation: not applicable
- Method of breeding: Parthenogenesis
- Feeding during test: not fed during exposure period

ACCLIMATION
- Not applicable

QUARANTINE (wild caught)
- Not applicable

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
48 h
Post exposure observation period:
Not applicable

Test conditions

Hardness:
The reconstituted water had an approximate theoretical total hardness of 250 mg/l as CaCO3.
Test temperature:
Recorded daily throughout the test using a Hanna Instruments HI 93510 digital thermometer.

Temperature maintained at 21°C to 22°C throughout the test.

Some of the temperatures were observed to be slightly in excess of the range given in the study plan of 20 ± 1°C. This deviation was considered not to have affected the outcome or the validity of the test as no adverse effects of exposure were observed throughout the duration of the test and that the temperature range was within guideline specification.
pH:
Recorded at start and termination of the test using a WTW pH/Oxi 340I pH and dissolved oxygen meter.

Range: 7.5 to 8.1
Dissolved oxygen:
Recorded at start and termination of the test using a WTW pH/Oxi 340I pH and dissolved oxygen meter.

The oxygen concentration in some of the test vessels at was observed to have an air saturation value (ASV) in excess of 100%. This was considered to be due to the presence of microscopic air bubbles in the media super-saturating the diluent and was considered not to have had an impact on the outcome or integrity of the test as no adverse effects were observed.
Salinity:
Not applicable, as freshwater study.
Nominal and measured concentrations:
Range-finder: 1.0, 10 and 100 mg/l

Definitive test: Nominal loading rate of 100 mg/l
Details on test conditions:
TEST SYSTEM
- Test vessel:250 ml glass jars
- Type: closed
- Material, size, headspace, fill volume: 250 ml glass jars containing approximately 250 ml of test preparation
- Aeration: not aerated
- Type of flow-through (e.g. peristaltic or proportional diluter): not applicable
- Renewal rate of test solution (frequency/flow rate): The test preparations were not renewed during the exposure period
- No. of organisms per vessel: 5 Daphnids
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): not applicable
- Biomass loading rate: not stated in report

TEST MEDIUM / WATER PARAMETERS
Stock Solutions
a) CaCl2.2H2O 11.76 g/l
b) MgSO4.7H2O 4.93 g/l
c) NaHCO3 2.59 g/l
d) KCl 0.23 g/l

Preparation
An aliquot (25 ml) of each of solutions a-d was added to each litre (final volume) of deionised water with a conductivity of <5 µS cm-1. The reconstituted water had a pH of 7.8 ± 0.2 adjusted (if necessary) with NaOH or HCl and was aerated until the dissolved oxygen concentration was approximately air-saturation value.


OTHER TEST CONDITIONS
- Adjustment of pH: not required
- Photoperiod: photoperiod of 16 hours light and 8 hours darkness with 20 minute dawn and dusk transition periods.
- Light intensity: not stated in report

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Any immobilisation or adverse reactions to exposure were recorded at 24 and 48 hours after the start of exposure. The criterion of effect used was that Daphnia were considered to be immobilised if they were unable to swim for approximately 15 seconds after gentle agitation.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: not applicable, as definitive test was a limit test
- Justification for using less concentrations than requested by guideline: Based on the results of the range-finding test a "Limit test" was conducted at a single loading rate of 100 mg/l to confirm that no immobilisation or adverse reactions to exposure were observed.

- Range finding study
- Test concentrations: 1.0, 10 and 100 mg/l loading rate
- Results used to determine the conditions for the definitive study: A single immobilised daphnid was observed at a test concentration of 1.0 mg/l after 24 hours exposure. This was considered to be due to natural causes rather than a toxic effect given that no other immobilisation was observed.
Based on this information, a single loading rate of four replicates, of 100 mg/l, using a stirring period of 23 hours followed by a 1-Hour standing period, was selected for the definitive test. This experimental design conforms to a "Limit test" to confirm that no immobilisation or adverse reactions to exposure were observed.
Reference substance (positive control):
yes
Remarks:
Potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
48 h
Dose descriptor:
EL50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
other: nominal loading rate WAF
Basis for effect:
other: immbolisation
Duration:
48 h
Dose descriptor:
NOELR
Effect conc.:
100 mg/L
Nominal / measured:
nominal
Conc. based on:
other: nominal loading rate WAF
Basis for effect:
other: immobilisation
Details on results:
- Behavioural abnormalities: None observed

- Observations on body length and weight: Not observed

- Other biological observations: Immobilisation only observed.

- Mortality of control: immobilisation only observed. Mortality not assessed.

- Other adverse effects control: none stated in report

- Abnormal responses: none stated in report

- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: Not applicable as WAFs used, so measured values not available

- Effect concentrations exceeding solubility of substance in test medium: No
Results with reference substance (positive control):
- Results with reference substance valid? Yes.

- Mortality: Not applicable

- EC50/LC50: The No Observed Effect Concentrations after 24 and 48 hours was 0.32 mg/l. The No Observed Effect Concentration is based upon zero immobilisation at this concentration.
The slope and its standard error of the response curve at 24 hours was 7.7 (SE = 1.6). Due to the unsuitable nature of the data it was not possible to calculate the slope and error of response curve at 48 hours.
The results from the positive control with potassium dichromate were within the normal range for this reference item. The mean 48-Hour EC50 value calculated from all positive controls was 0.77 mg/l (sd = 0.20).

Reported statistics and error estimates:
Analysis of the mortality data was by the probit method (Finney 1971) at 24 hours and the trimmed Spearman-Karber method (Hamilton et al 1977) at 48 hours using the ToxCalc computer software package (ToxCalc 1999).
Probit analysis is used when two or more partial responses to exposure are shown.

Any other information on results incl. tables

Validation of Mixing Period

Pre-study work indicated that there was no significant increase in the amount of total organic carbon by extending the preparation period for longer than 24 hours. As such, for the purposes of testing, the WAF was prepared using a stirring period of 23 hours followed by a 1 -Hour standing period.

Range-finding Test

Cumulative immobilisation data from the exposure of Daphnia magna to the test item during the range-finding test are given inTable1.

No significant immobilisation was observed at the 1.0, 10 and 100 mg/l loading rate WAFs.

Immobilisation data

Cumulative immobilisation data from the exposure of Daphnia magna to the test item during the definitive test are given in Table 2.

There was no immobilisation in 20 daphnids exposed to a 100 mg/l loading rate WAF for a period of 48 hours. Inspection of the immobilisation data gave the following results:

Time (h)

EL*50(mg/l)

24

>100

48

>100

The No Observed Effect Loading rate after 24 and 48 hours exposure was 100 mg/l loading rate WAF. The No Observed Effect Loading rate is based upon zero immobilisation at this loading rate.

It was considered unnecessary and unrealistic to test at loading rates in excess of 100 mg/l.


*EL = Effective Loading rate

 Vortex depth measurements

The vortex depth was recorded at the start and end of the mixing period and was observed to be a dimple at the water surface on each occasion.

Observations on test item solubility

Observations on the test media were carried out during the mixing and testing of the WAFs.

At the start of the mixing period the 100 mg/l loading rate was observed to be a clear, colourless water column, with test item floating on the surface. After 23 hours stirring and a 1-Hour standing period the 100 mg/l loading rate was observed to remain a clear, colourless water column with test item floating on the surface. Microscopic examination of the WAF showed micro-dispersions of test item to be present and therefore it was considered appropriate to remove the WAF by filtering through a glass wool plug (2-4 cm in length). Microscopic examination after filtering showed the glass wool plug had removed all the micro-dispersions of the test item. During the test the 100 mg/l loading rate was observed to be a clear, colourless solution.

Total organic carbon analysis

Total Organic Carbon (TOC) analysis of the test preparations was conducted at 0 and 48 hours. Given the background level of carbon in the control vessels and also the low level of carbon in the test vessels, it was considered that the results gave no evidence of the presence of test item in the WAF.

Given that toxicity cannot be attributed to a single component or mixture of components but to the test item as a whole and the dissolved test item was below the quantifiable limit of the analytical method, the results were based on nominal loading rates only.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The 48-Hour EL*50 for the test item to Daphnia magna based on nominal loading rates was greater than 100 mg/l loading rate WAF and correspondingly the No Observed Effect Loading rate was 100 mg/l loading rate WAF.
Executive summary:

Introduction.A study was performed to assess the acute toxicity of the test item to Daphnia magna.  The method followed that described in the OECD Guidelines for Testing of Chemicals (April 2004) No 202, "Daphnia sp, Acute Immobilisation Test" referenced as Method C.2 of Commission Regulation (EC) No. 440/2008.

Methods. Following a preliminary range-finding test, twenty daphnids (4 replicates of 5 animals) were exposed to a Water Accommodated Fraction (WAF) of the test item, at a single nominal loading rate of 100 mg/l for 48 hours at a temperature of 21°C to 22°C under static test conditions. Immobilisation and any adverse reactions to exposure were recorded after 24 and 48 hours.

A positive control conducted approximately every six months used potassium dichromate as the reference item. Daphnia magnawas exposed to an aqueous solution of the reference item at concentrations of 0.32, 0.56, 1.0, 1.8 and 3.2 mg/l for 48 hours at a temperature of approximately 20°C under static test conditions. Immobilisation and any adverse reactions to exposure were recorded after 24 and 48 hours.

Results. The 48-Hour EL*50for the test item to Daphnia magna based on nominal loading rates was greater than 100 mg/l loading rate WAF and correspondingly the No Observed Effect Loading rate was 100 mg/l loading rate WAF.

It was considered unnecessary and unrealistic to test at loading rates in excess of 100 mg/l.

Samples of the control and 100 mg/l loading rate WAFs were taken at 0 (fresh media) and 48 hours (old media) for Total Organic Carbon (TOC) analysis. Given the background level of carbon in the control vessels and also the low level of carbon in the test vessels, it was considered that the results gave no evidence of the presence of test item in the WAF.

Therefore, given that the toxicity cannot be attributed to a single component or a mixture of components but to the test item as a whole, and the dissolved test item was below the quantifiable limit of the analytical method, the results were based on nominal loading rates only.

The 48-Hour EC50for the reference item (potassium dichromate) to Daphnia magna based on nominal concentrations was 0.65 mg/l with 95% confidence limits of 0.58 – 0.72 mg/l. The No Observed Effect Concentration was 0.32 mg/l.


*EL = Effective Loading rate