Reaction mass of 4-methyl-2-phenyl-3,6-dihydro-2H-pyran and 4-methyl-6-phenyl-3,6-dihydro-2H-pyran and 4-methylene-2-phenyltetrahydro-2H-pyran

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

11-02-2013 to 27-04-2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study performed under GLP. All relevant validity criteria were met.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

inspected: July 2012 ; signature: November 2012

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0.10, 0.32, 1.0, 3.2, 10.0 and 100% v/v nominal.
- Sampling method: Water samples were taken from the control and each test group (replicates R1 - R4 pooled) at 0 and 48 hours for quantitative analysis.
- Sample storage conditions before analysis: Analysed on day of receipt. Duplicate samples were taken and stored at approximately -20 °C for further analysis if necessary. Diluted with acetonitrile.

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphinds
- Strain: Daphnia magna
- Source: in-house laboratory cultures
- Age at study initiation (mean and range, SD): Gravid adults were isolated the day before initiation of the test, such that the young daphnids produced overnight were less than 24 hours old.
- Method of breeding: Parthenogenesis
- Feeding during test: Yes.
- Food type: Algal suspension (Desmodesmus subspicatus) and Tetramin® flake food suspension
- Amount: Not reported.
- Frequency: Daily

ACCLIMATION
- Acclimation period: None.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

Reconstituted water had an approximate theoretical total hardness of 250 mg/L as CaCO3

Test temperature:

20 °C. Refer to table 1 for information on temperature in the definitive test.

pH:

Rconstituted water had a pH of 7.8 ± 0.2 adjusted (if necessary) with NaOH or HCl. Refer to table 1 for information on pH in the definitive test.

Dissolved oxygen:

Reconstituted water was aerated until the dissolved oxygen concentration was approximately air-saturation value. Refer to table 1 for information ondesolved oxygen in the definitive test.

Nominal and measured concentrations:

Range-finding test : nominal test concentrations of 0.10, 1.0, 10 and 100% v/v saturated solution.
Definitive test: 0.10, 0.32, 1.0, 3.2, 10, 32 and 100% v/v saturated solution

Details on test conditions:

TEST SYSTEM
- Test vessel: 150 ml
- Type (delete if not applicable): Closed.
- Material, size, headspace, fill volume: Glass 150 ml, completely filled or ca. 130ml to minimise headspace.
- Aeration: No aeration of the test solutions.
- No. of organisms per vessel: RF test: 10 per concentration and control vessel ; Definitive test: 20 per concentration, 5 per vessel
- No. of vessels per concentration (replicates): 4 (four) replicates, 5 daphnia per vessel.
- No. of vessels per control (replicates): 4 (four) replicates, 5 daphnia per vessel.
- No. of vessels per vehicle control (replicates): Not applicable.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted Water was used as dilution water and prepared from deionised water with conductivity <5 uS cm-1 and pH 7.8 ± 0.2 and 25ml of stock solutions of a. CaCl2.2H2O 11.76 g/L, b. MgSO4.1H2O 4.93 g/L, c. NaHCO3 2.59 g/l, and d. KCl 0.23 g/l.
- Culture medium different from test medium: No, M7 Medium used for culture and test medium

OTHER TEST CONDITIONS
- Adjustment of pH: None.
- Photoperiod: 16 hours light; 8 hours dark photoperiod daily; with 20 minute dawn and dusk transition periods
- Light intensity: Not reported.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Immobility (including mortality), 24 hours and at 48 hours.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3.2
- Justification for using less concentrations than requested by guideline: Not applicable.
- Range finding study
- Test concentrations: 0, 0.1, 1.0, 10 and 100% (v/v) saturated solution
- Results used to determine the conditions for the definitive study: Yes.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

21 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CL: 12 to 38 mg/l

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

12 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

38 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: None
- Observations on body length and weight: Not applicable.
- Other biological observations:
- Mortality of control: No mortalities.
- Other adverse effects control: None.
- Abnormal responses: None.
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: The test preparations were observed to be clear colourless solutions at 0 and 24 hours. However, at 48 hours the 100% v/v saturated solution test concentration was observed to be a clear colourless water column with oily globules of test item dispersed throughout. This indicates that the test item precipitated out of solution between 24 and 48 hours in this test concentration and could have been caused by undissolved test item being forced through the filter. This was thought not to have contributed to the immobilization observed at this concentration as immobilization was also observed at 10 and 32% v/v saturated solution where no precipitated test item was observed.
- Effect concentrations exceeding solubility of substance in test medium: No.

Results with reference substance (positive control):

- Results with reference substance valid?: Yes.
- Mortality: None reported. Acute immobilisation reported only.
- EC50/LC50: 24h-EC50 was 0.75 mg/l with a 95% confidence interval between 0.56 and 1.0 mg/l. 48h-EC50 was 0.45 mg/l with a 95% confidence interval between 0.42 and 0.48 mg/l. The results from the positive control with potassium dichromate were within the normal range for this reference item.
- Other: Exposure conditions for the positive control were similar to those in the definitive test.

Table 1. Physico-Chemical Measurements

Mean Measured Concentration (mg/L)		0 Hours				24 Hours	48 Hours
		pH	mg O2/L	%ASV*	T °C	T °C	pH	mg O2/L	%ASV*	T °C
Control	R1	7.7	8.8	97	20	20	7.7	9.1	100	20
	R2	7.7	8.9	98	20	20	7.7	9.1	100	20
	R3	7.7	8.8	97	20	20	7.7	9.1	100	20
	R4	7.7	8.8	97	20	20	7.7	9.0	99	20
0.40	R1	7.8	8.8	97	20	20	7.8	8.6	96	20
	R2	7.7	8.8	97	20	20	7.8	8.9	98	20
	R3	7.7	8.8	97	20	20	7.8	9.0	99	20
	R4	7.7	8.5	93	20	20	7.8	9.0	99	20
1.2	R1	7.7	8.9	98	20	20	7.8	8.8	97	20
	R2	7.7	8.8	97	20	20	7.9	8.9	98	20
	R3	7.6	8.9	98	20	20	7.9	9.0	99	20
	R4	7.6	8.8	97	20	20	7.9	9.0	99	20
3.4	R1	7.6	8.8	97	20	20	7.9	8.7	96	20
	R2	7.6	8.8	97	20	20	7.9	8.8	97	20
	R3	7.6	8.8	97	20	20	7.9	8.8	97	20
	R4	7.6	8.8	97	20	20	7.9	8.9	98	20
12	R1	7.5	8.8	97	20	20	7.9	8.8	97	20
	R2	7.4	8.8	97	20	20	7.9	8.7	96	20
	R3	7.4	8.9	98	20	20	7.9	8.8	97	20
	R4	7.4	8.9	98	20	20	7.9	8.7	96	20
37	R1	7.4	8.8	97	20	20	7.9	8.4	92	20
	R2	7.4	8.8	97	20	20	7.9	8.4	92	20
	R3	7.3	8.8	97	20	20	7.9	8.4	92	20
	R4	7.3	8.8	97	20	20	7.9	8.4	92	20
125	R1	7.3	8.8	97	20	20	7.9	8.6	95	20
	R2	7.3	8.8	97	20	20	7.9	8.7	96	20
	R3	7.3	8.8	97	20	20	7.9	8.7	96	20
	R4	7.2	8.8	97	20	20	7.9	8.7	96	20
294	R1	7.2	8.8	97	20	20	7.9	8.8	97	20
	R2	7.2	8.8	97	20	20	8.0	9.0	99	20
	R3	7.2	8.8	97	20	20	8.0	9.0	99	20
	R4	7.2	8.7	96	20	20	8.0	8.8	97	20

*ASV = Dissolved oxygen concentration expressed as a percentage of Air Saturation Value

R1 – R4 = Replicates 1 to 4

 

Table 2. Cumulative Immobilization Data in the Range-finding Test

Nominal Concentration (% v/v Saturated Solution)	0-Hour Measured Concentration (mg/L)	Cumulative Immobilized Daphnia (Initial Population: 10 Per Replicate)
		24 Hours	48 Hours
Control	-	0	0
0.10	0.25	0	0
1.0	2.3	0	3
10	20	0	5
100	130	10	10

  - = not applicable

 

Table 3. Cumulative Immobilization Data in the Definitive Test

Nominal Concentration (%v/v Saturated Solution)	0-Hour Measured Concentration (mg/L)	Cumulative Immobilized Daphnia (Initial Population: 5 Per Replicate)
		24 Hours						48Hours
		R1	R2	R3	R4	Total	%	R1	R2	R3	R4	Total	%
Control	.	0	0	0	0	0	0	0	0	0	0	0	0
0.10	0.38	0	0	0	0	0	0	0	0	0	0	0	0
0.32	1.2	0	0	0	0	0	0	0	0	0	0	0	0
1.0	3.1	0	0	0	0	0	0	0	0	0	0	0	0
3.2	12	0	0	0	0	0	0	0	0	0	0	0	0
10	38	3	3	3	3	12	60	5	5	5	5	20	100
32	133	5	5	5	5	20	100	5	5	5	5	20	100
100	304	5	5	5	5	20	100	5	5	5	5	20	100

R1 – R4 = Replicates 1 to 4

  - = not applicable

Validity criteria fulfilled:

yes

Conclusions:

The test item 48h-EC50 was 21 (95% CL: 12 – 38) mg/L based on 0-hour analytically measured concentrations.

Executive summary:

The acute toxicity to Daphnia magna was carried out according to OECD 202 Daphnia sp., Acute Immobilisation Test and EU Method C.2 guidelines under GLP. A pre-study media preparation trial indicated that the use of a saturated solution method of preparation was most appropriate for this test item. Following a preliminary range-finding test, twenty daphnids (4 replicates of 5 daphnids) were exposed to an aqueous solution of the test item at nominal concentrations of 0.1 0, 0.32, 1.0, 3.2, 10, 32 and 100% v/v saturated solution for 48 hours at a temperature of approximately 20 °C under static test conditions. The test item solution was prepared by stirring an excess (500 mg/L) of test item in test medium using a propeller stirrer at approximately 1500 rpm for 24 hours. After the stirring period any undissolved test item was removed by filtration (0.2 um Gelman Acrocap filter, first approximate 500 mL discarded in order to pre-condition the filter) to produce a 100% v/v saturated solution of the test item. The number of immobilized Daphnia were recorded after 24 and 48 hours. Analysis of the freshly prepared media at 0 hours for the 0.10, 0.32, 1.0, 3.2, 10, 32 and 100% v/v saturated solution test concentrations showed measured concentrations of between 0.38 and 304 mg/L. Analysis of the old media at 48 hours for the 0.10, 0.32, 1.0, 3.2, 10, 32 and 100% v/v saturated solution test concentration showed measured concentrations of between 0.42 and 284 mg/L. As the measured concentrations at 48 hours were between 93 - 118% of the measured concentrations at 0 hours, it was considered justifiable to base the results on the 0-Hour measured concentrations. The study met the acceptability criteria prescribed by the guideline. The 48h-EC50 was 21 (95% CL: 12 – 38) mg/L based on 0-hour analytically measured concentrations.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

key study

Study period:

11-02-2013 to 27-04-2013

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study performed under GLP. All relevant validity criteria were met.

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Further information is included in attachment to IUCLID section 13.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The read-across is based on the hypothesis that the source and target substances have common structural features in the same relative positions. The source and target have similar physico-chemical, toxicological properties and because of common metabolism they share common or have similar breakdown products and therefore potential mechanisms of action. Further information is included in attachment to IUCLID section 13.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
The source and target chemicals have comparable chemical similarity. Further information is included in attachment to IUCLID section 13

3. ANALOGUE APPROACH JUSTIFICATION
The source substance is a chemically similar substance with common metabolism and common or similar degradants of the target substance. Further information is included in attachment to IUCLID section 13

4. DATA MATRIX
Further information is included in attachment to IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

inspected: July 2012 ; signature: November 2012

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0.10, 0.32, 1.0, 3.2, 10.0 and 100% v/v nominal.
- Sampling method: Water samples were taken from the control and each test group (replicates R1 - R4 pooled) at 0 and 48 hours for quantitative analysis.
- Sample storage conditions before analysis: Analysed on day of receipt. Duplicate samples were taken and stored at approximately -20 °C for further analysis if necessary. Diluted with acetonitrile.

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphinds
- Strain: Daphnia magna
- Source: in-house laboratory cultures
- Age at study initiation (mean and range, SD): Gravid adults were isolated the day before initiation of the test, such that the young daphnids produced overnight were less than 24 hours old.
- Method of breeding: Parthenogenesis
- Feeding during test: Yes.
- Food type: Algal suspension (Desmodesmus subspicatus) and Tetramin® flake food suspension
- Amount: Not reported.
- Frequency: Daily

ACCLIMATION
- Acclimation period: None.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

Reconstituted water had an approximate theoretical total hardness of 250 mg/L as CaCO3

Test temperature:

20 °C. Refer to table 1 for information on temperature in the definitive test.

pH:

Rconstituted water had a pH of 7.8 ± 0.2 adjusted (if necessary) with NaOH or HCl. Refer to table 1 for information on pH in the definitive test.

Dissolved oxygen:

Reconstituted water was aerated until the dissolved oxygen concentration was approximately air-saturation value. Refer to table 1 for information ondesolved oxygen in the definitive test.

Nominal and measured concentrations:

Range-finding test : nominal test concentrations of 0.10, 1.0, 10 and 100% v/v saturated solution.
Definitive test: 0.10, 0.32, 1.0, 3.2, 10, 32 and 100% v/v saturated solution

Details on test conditions:

TEST SYSTEM
- Test vessel: 150 ml
- Type (delete if not applicable): Closed.
- Material, size, headspace, fill volume: Glass 150 ml, completely filled or ca. 130ml to minimise headspace.
- Aeration: No aeration of the test solutions.
- No. of organisms per vessel: RF test: 10 per concentration and control vessel ; Definitive test: 20 per concentration, 5 per vessel
- No. of vessels per concentration (replicates): 4 (four) replicates, 5 daphnia per vessel.
- No. of vessels per control (replicates): 4 (four) replicates, 5 daphnia per vessel.
- No. of vessels per vehicle control (replicates): Not applicable.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted Water was used as dilution water and prepared from deionised water with conductivity <5 uS cm-1 and pH 7.8 ± 0.2 and 25ml of stock solutions of a. CaCl2.2H2O 11.76 g/L, b. MgSO4.1H2O 4.93 g/L, c. NaHCO3 2.59 g/l, and d. KCl 0.23 g/l.
- Culture medium different from test medium: No, M7 Medium used for culture and test medium

OTHER TEST CONDITIONS
- Adjustment of pH: None.
- Photoperiod: 16 hours light; 8 hours dark photoperiod daily; with 20 minute dawn and dusk transition periods
- Light intensity: Not reported.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Immobility (including mortality), 24 hours and at 48 hours.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3.2
- Justification for using less concentrations than requested by guideline: Not applicable.
- Range finding study
- Test concentrations: 0, 0.1, 1.0, 10 and 100% (v/v) saturated solution
- Results used to determine the conditions for the definitive study: Yes.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

21 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CL: 12 to 38 mg/l

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

12 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

38 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: None
- Observations on body length and weight: Not applicable.
- Other biological observations:
- Mortality of control: No mortalities.
- Other adverse effects control: None.
- Abnormal responses: None.
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: The test preparations were observed to be clear colourless solutions at 0 and 24 hours. However, at 48 hours the 100% v/v saturated solution test concentration was observed to be a clear colourless water column with oily globules of test item dispersed throughout. This indicates that the test item precipitated out of solution between 24 and 48 hours in this test concentration and could have been caused by undissolved test item being forced through the filter. This was thought not to have contributed to the immobilization observed at this concentration as immobilization was also observed at 10 and 32% v/v saturated solution where no precipitated test item was observed.
- Effect concentrations exceeding solubility of substance in test medium: No.

Results with reference substance (positive control):

- Results with reference substance valid?: Yes.
- Mortality: None reported. Acute immobilisation reported only.
- EC50/LC50: 24h-EC50 was 0.75 mg/l with a 95% confidence interval between 0.56 and 1.0 mg/l. 48h-EC50 was 0.45 mg/l with a 95% confidence interval between 0.42 and 0.48 mg/l. The results from the positive control with potassium dichromate were within the normal range for this reference item.
- Other: Exposure conditions for the positive control were similar to those in the definitive test.

Table 1. Physico-Chemical Measurements

Mean Measured Concentration (mg/L)		0 Hours				24 Hours	48 Hours
		pH	mg O2/L	%ASV*	T °C	T °C	pH	mg O2/L	%ASV*	T °C
Control	R1	7.7	8.8	97	20	20	7.7	9.1	100	20
	R2	7.7	8.9	98	20	20	7.7	9.1	100	20
	R3	7.7	8.8	97	20	20	7.7	9.1	100	20
	R4	7.7	8.8	97	20	20	7.7	9.0	99	20
0.40	R1	7.8	8.8	97	20	20	7.8	8.6	96	20
	R2	7.7	8.8	97	20	20	7.8	8.9	98	20
	R3	7.7	8.8	97	20	20	7.8	9.0	99	20
	R4	7.7	8.5	93	20	20	7.8	9.0	99	20
1.2	R1	7.7	8.9	98	20	20	7.8	8.8	97	20
	R2	7.7	8.8	97	20	20	7.9	8.9	98	20
	R3	7.6	8.9	98	20	20	7.9	9.0	99	20
	R4	7.6	8.8	97	20	20	7.9	9.0	99	20
3.4	R1	7.6	8.8	97	20	20	7.9	8.7	96	20
	R2	7.6	8.8	97	20	20	7.9	8.8	97	20
	R3	7.6	8.8	97	20	20	7.9	8.8	97	20
	R4	7.6	8.8	97	20	20	7.9	8.9	98	20
12	R1	7.5	8.8	97	20	20	7.9	8.8	97	20
	R2	7.4	8.8	97	20	20	7.9	8.7	96	20
	R3	7.4	8.9	98	20	20	7.9	8.8	97	20
	R4	7.4	8.9	98	20	20	7.9	8.7	96	20
37	R1	7.4	8.8	97	20	20	7.9	8.4	92	20
	R2	7.4	8.8	97	20	20	7.9	8.4	92	20
	R3	7.3	8.8	97	20	20	7.9	8.4	92	20
	R4	7.3	8.8	97	20	20	7.9	8.4	92	20
125	R1	7.3	8.8	97	20	20	7.9	8.6	95	20
	R2	7.3	8.8	97	20	20	7.9	8.7	96	20
	R3	7.3	8.8	97	20	20	7.9	8.7	96	20
	R4	7.2	8.8	97	20	20	7.9	8.7	96	20
294	R1	7.2	8.8	97	20	20	7.9	8.8	97	20
	R2	7.2	8.8	97	20	20	8.0	9.0	99	20
	R3	7.2	8.8	97	20	20	8.0	9.0	99	20
	R4	7.2	8.7	96	20	20	8.0	8.8	97	20

*ASV = Dissolved oxygen concentration expressed as a percentage of Air Saturation Value

R1 – R4 = Replicates 1 to 4

 

Table 2. Cumulative Immobilization Data in the Range-finding Test

Nominal Concentration (% v/v Saturated Solution)	0-Hour Measured Concentration (mg/L)	Cumulative Immobilized Daphnia (Initial Population: 10 Per Replicate)
		24 Hours	48 Hours
Control	-	0	0
0.10	0.25	0	0
1.0	2.3	0	3
10	20	0	5
100	130	10	10

  - = not applicable

 

Table 3. Cumulative Immobilization Data in the Definitive Test

Nominal Concentration (%v/v Saturated Solution)	0-Hour Measured Concentration (mg/L)	Cumulative Immobilized Daphnia (Initial Population: 5 Per Replicate)
		24 Hours						48Hours
		R1	R2	R3	R4	Total	%	R1	R2	R3	R4	Total	%
Control	.	0	0	0	0	0	0	0	0	0	0	0	0
0.10	0.38	0	0	0	0	0	0	0	0	0	0	0	0
0.32	1.2	0	0	0	0	0	0	0	0	0	0	0	0
1.0	3.1	0	0	0	0	0	0	0	0	0	0	0	0
3.2	12	0	0	0	0	0	0	0	0	0	0	0	0
10	38	3	3	3	3	12	60	5	5	5	5	20	100
32	133	5	5	5	5	20	100	5	5	5	5	20	100
100	304	5	5	5	5	20	100	5	5	5	5	20	100

R1 – R4 = Replicates 1 to 4

  - = not applicable

Validity criteria fulfilled:

yes

Conclusions:

The target substance 48h-EC50 is expected to be 21 (95% CL: 12 – 38) mg/L based on 0-hour analytically measured concentrations.

Executive summary:

The acute toxicity to Daphnia magna was carried out on a source substance according to OECD 202 Daphnia sp., Acute Immobilisation Test and EU Method C.2 guidelines under GLP. A pre-study media preparation trial indicated that the use of a saturated solution method of preparation was most appropriate for this test item. Following a preliminary range-finding test, twenty daphnids (4 replicates of 5 daphnids) were exposed to an aqueous solution of the test item at nominal concentrations of 0.1 0, 0.32, 1.0, 3.2, 10, 32 and 100% v/v saturated solution for 48 hours at a temperature of approximately 20 °C under static test conditions. The test item solution was prepared by stirring an excess (500 mg/L) of test item in test medium using a propeller stirrer at approximately 1500 rpm for 24 hours. After the stirring period any undissolved test item was removed by filtration (0.2 um Gelman Acrocap filter, first approximate 500 mL discarded in order to pre-condition the filter) to produce a 100% v/v saturated solution of the test item. The number of immobilized Daphnia were recorded after 24 and 48 hours. Analysis of the freshly prepared media at 0 hours for the 0.10, 0.32, 1.0, 3.2, 10, 32 and 100% v/v saturated solution test concentrations showed measured concentrations of between 0.38 and 304 mg/L. Analysis of the old media at 48 hours for the 0.10, 0.32, 1.0, 3.2, 10, 32 and 100% v/v saturated solution test concentration showed measured concentrations of between 0.42 and 284 mg/L. As the measured concentrations at 48 hours were between 93 - 118% of the measured concentrations at 0 hours, it was considered justifiable to base the results on the 0-Hour measured concentrations. The study met the acceptability criteria prescribed by the guideline. The 48h-EC50 was 21 (95% CL: 12 – 38) mg/L based on 0-hour analytically measured concentrations.

Description of key information

48-h EC50 (Read-Across: 4-methyl-2-phenyltetrahydro-2H-pyran ; aquatic invertebrates) = 21 mg/L (C.I. 12 – 38 mg/L) based on 0-hour measured concentrations, 48-hour, freshwater, OECD TG 202, 2013

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

21 mg/L

Additional information

Key study : OECD TG 202, 2013 : Read-Across - SOURCE (4-methyl-2-phenyltetrahydro-2H-pyran): The acute toxicity to Daphnia magna was carried out according to OECD 202 Daphnia sp., Acute Immobilisation Test and EU Method C.2 guidelines under GLP. A pre-study media preparation trial indicated that the use of a saturated solution method of preparation was most appropriate for this test item. Following a preliminary range-finding test, twenty daphnids (4 replicates of 5 daphnids) were exposed to an aqueous solution of the test item at nominal concentrations of 0.1 0, 0.32, 1.0, 3.2, 10, 32 and 100% v/v saturated solution for 48 hours at a temperature of approximately 20 °C under static test conditions. The test item solution was prepared by stirring an excess (500 mg/L) of test item in test medium using a propeller stirrer at approximately 1500 rpm for 24 hours. After the stirring period any undissolved test item was removed by filtration (0.2 um Gelman Acrocap filter, first approximate 500 mL discarded in order to pre-condition the filter) to produce a 100% v/v saturated solution of the test item. The number of immobilized Daphnia were recorded after 24 and 48 hours. Analysis of the freshly prepared media at 0 hours for the 0.10, 0.32, 1.0, 3.2, 10, 32 and 100% v/v saturated solution test concentrations showed measured concentrations of between 0.38 and 304 mg/L. Analysis of the old media at 48 hours for the 0.10, 0.32, 1.0, 3.2, 10, 32 and 100% v/v saturated solution test concentration showed measured concentrations of between 0.42 and 284 mg/L. As the measured concentrations at 48 hours were between 93 - 118% of the measured concentrations at 0 hours, it was considered justifiable to base the results on the 0-Hour measured concentrations. The study met the acceptability criteria prescribed by the guideline. The 48h-EC50 was 21 (95% CL: 12 – 38) mg/L based on 0-hour analytically measured concentrations.