benzyl(diethylamino)diphenylphosphonium 4-[1,1,1,3,3,3-hexafluoro-2-(4-hydroxyphenyl)propan-2-yl]phenolate

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

September 9 to October 11, 2013

Reliability:

2 (reliable with restrictions)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

Due to the low water solubility of the test item, the organisms were exposed to a Water Accomodated Fraction (WAF) of the substance.

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

yes

Remarks:

Due to the low water solubility of the test item, the organisms were exposed to a Water Accomodated Fraction (WAF) of the substance.

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

XA31

IUPAC Name:

XA31

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

Name of the test item (as cited in the study report): XA31
Description: off-white powder;
Storage conditions: room temperature in the dark

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

1st instar Daphnia magna derived from in-house laboratory cultures. Adult Daphnia were mainteined in 150mL glass beakers containing Elendt M7 medium in a temperature controlled room at approximately 20°C. The lighting cycle was controlled to give a 16hours light and 8 hours darkness cycle with 20 minute dawn and dusk tansition periods.
Gravid adults were isolated the day before initiation of the test, such that the young daphnids produced overnight were less than 24hours old. The young were removed from the cultures and uses for testing. The diet and diluent water are considered not to contain any contaminant that would affect the integrity or outcome of the study.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

The number of immobilized Daphnia and any adverse reactions to exposure were recorded after 24 and 48 hrs.

Test conditions

Hardness:

250 mg/l as CaCO3

Test temperature:

app. 21°C

pH:

7.8 +/- 0.2

Nominal and measured concentrations:

nominal loading rated of 1.0, 1.8, 3.2, 5.6 and 10 mg/L.

Details on test conditions:

20 daphnids (4 replicates of 5 animals) were exposed to Water Accomodated Fractions (WAFs) of the test item for 48 h at temperature of app. 21°C under static test conditions

Reference substance (positive control):

yes

Remarks:

potassium dichromate at concentrations of 0.32, 0.56, 1.0, 1.8 and 3.2 mg/l

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 7.4-8.7

Any other information on results incl. tables

Range-Finding Test

Cumulative immobilization data from the exposure of Daphnia Magna to the test item during the range-finding test are give in Table 1

Nominal Loading Rate (mg/L)	Cumulatie Immobilized Daphnia (Initial Population: 10 per replicate)
	24 h	48 h
Control	0	0
1	0	0
10	10	10
100	10	10

 

No immobilization was observed at 1.0 mg/L loading rate WAF. However, immobilization was observed at 10 and 100 mg/L loading rate WAF.

Based on this information loading rates of 1, 1.8, 3.2, 5.6 and 10 mg/L were selected for the definitive test.

Analysis of the 1, 10 and 100 mg/L loading rate WAFs at 0hours showed measured concentrations of 0.0015, 0.022 and 0.071 mg/L respectively. 1, 10 and 100 mg/L loading rate WAFs at 48hours showed measured concentrations of 0.00052, 0.022 and 0.066 mg/L respectively. The slight decline in measured concentration observed in the 1 mg/L loading rate over the test period was due to an error in sampling, whereby the control was sampled in error and not discarded prior to sampling the 1.0mg/L loading rate, rather than true instability of the test item.

Definitive Test

Chemical Analysis of Test Loading Rates

Analysis of the 5.6 and 10 mg/L loading rate WAFs at 0 hour showed measured concentrations of 0.0086 and 0.016 mg/L respectively. Analysis of the 5.6 and 10 mg/L loading rate WAFs at 48hours showed measured concentrations of 0.0081 and 0.016 respectively.

The toxicity of the test item cannot be attributed to a single component or a mixture of components but to the test item as a whole. In addition, the measured concentration obtained for the WAFs are not stability indicating and are rather a confirmation that the test item is present.

Immobilization Data

Analysis of the immobilization data by the trimmed Spearman-Karber method at 24 and 48 hours based on the nominal loading rates gave the following results:

Time (h)	EL50 (mg/L Loading Rate WAF)	95% Confidence limits (mg/L Loading Rate WAF)
24	9.5	7.7 – 12
48	8.0	7.4 – 8.7

 

The No Observed Effect Loading rate after 24 and 48 hours exposure was 5.6 mg/L loading rate WAF. Correspondingly the Lowest Effect Loading rate was considered to be 10mg/L loading rate WAF.

Significant immobilization was observed in the 1.8 mg/L loading rate WAF test group. However, this was considered not to be a true toxic effect of the test item as this did not follow a concentration, dependent pattern. In addition, both surviving and immobilized daphnids in this test group were observed to be trapped on the surface. As this effect was not observed in any other test group, this effect was considered not to be a true toxic effect of the test item but due to possible contamination of the test preparation. Single immobilized daphnids were observed in the control and 3.2 mg/L loading rate WAF groups however these were considered not to be true toxic effects as less than 10%immobilization occurred.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Analysis of the 5.6 and 10 mg/L loading rate WAFs at 0 hour showed measured concentrations of 0.0086 and 0.016 mg/L respectively. Analysis of the 5.6 and 10 mg/L loading rate WAFs at 48hours showed measured concentrations of 0.0081 and 0.016 respectively.
The toxicity of the test item cannot be attributed to a single component or a mixture of components but to the test item as a whole. In addition, the measured concentration obtained for the WAFs are not stability indicating and are rather a confirmation that the test item is present.
Exposure of the freshwater invertebrate Daphnia Magna to the test item has been investigated and gave the following results:
EL50 (Loading Rate WAF) 48 hrs = 8.0 mg/l
NOEL (Loading Rate WAF) = 5.6 mg/l
LOEL (Loading Rate WAF) = 10 mg/l

Executive summary:

A study was performed to assess the acute toxicity of the test item to Daphnia magna.

The method followed was designed to be compatible with the OECD Guideline 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.

Exposure of the freshwater invertebrate Daphnia Magna to the test item has been investigated and gave the following results:

Time (h)	EL50 (mg/L Loading Rate WAF)	95%Confidence limits (mg/L Loading Rate WAF)	NOEL (mg/L Loading Rate WAF)	LOEL (mg/L Loading Rate WAF)
48	8.0	7.4 – 8.7	5.6	10