3-(p-methoxyphenyl)-2-methylpropionaldehyde

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29 Jan 2017 to 8 March 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

1992

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Version / remarks:

2008

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Water samples were taken from the control and all surviving test vessels at 0, 24, 48 and 72 hours from fresh media, and at 24, 48, 72 and 96 hours from old media, for quantitative analysis. The samples were stored frozen prior to analysis. Duplicate samples at 0 (fresh media), 24 (old media), 72 hours (fresh media) and 96 hours (old media) were taken and stored frozen for further analysis, if necessary. The concentration and stability of the test item in the test preparations were verified by chemical analysis of the fresh media at 0 and 72 hours, and of the old media at 24 and 96 hours.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
A nominal amount of test item (1100 mg) was dispersed in 11 liters of test water with the aid of propeller stirring at approximately 1500 rpm for 24 hours. After 24 hours, the stirring was stopped and any undissolved test item was removed by filtration through a 0.2 µm filter (first approximate 1 liter discarded in order to pre-condition the filter) to give a 100% v/v saturated solution. A series of dilutions was made from this saturated solution to give test solutions of 0.78, 1.56, 3.125, 6.25 and 12.5% v/v saturated solution.

While the preliminary media preparation trial suggested to discard approximately the first 2 liters in order to pre-condition the filter, an error on the test item preparation pages for the threshold and definitive tests instructed to discard 1 liter. The preliminary media preparation trial did not suggest a significant difference in measured concentrations of test item depending on the amount of initial solution discarded, and analytical results indicate that there was not a significant difference in the measured concentrations of fresh test solutions. This error was therefore considered not to have had an adverse effect on the outcome of the study. The test preparations were mixed with a flat bladed stirrer for approximately 1 minute to ensure adequate mixing and homogeneity.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: rainbow trout
- Source: Brow Well Fisheries Limited, Hebden, near Skipton, Yorkshire, UK
- Age at study initiation: Juvenile fish were obtained at 06 January 2017 and maintained in-house till start of test
- Holding: Fish were maintained in a glass fiber tank with a "single pass" water renewal system.
- Length at study initiation: mean standard length of 5.1 cm (sd = 0.3)
- Weight at study initiation: 1.1 g (sd = 0.23)

ACCLIMATION
- Acclimation period: Fish were acclimatized to test conditions from 13 February 2017 to 20 February 2017.
- Acclimation conditions (same as test or not): same as test
- Feeding: The stock fish were fed commercial trout pellets, which were discontinued approximately 23 hours prior to the start of the definitive test.
- Health during acclimation: There was no mortality in the 7 days prior to the start of the test

FEEDING DURING TEST: No

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

140 mg/L as CaCO3

Test temperature:

14 - 15 °C

pH:

7.6 - 8.1

Dissolved oxygen:

8.5 - 11.5 mg/L

Nominal and measured concentrations:

- Nominal concentrations: 0 (control), 0.78, 1.56, 3.125, 6.25 and 12.5% v/v saturated solution; 100% satured solution prepared of 100 mg test substance/L
- Measured concentrations (average geometric means): 0 (control), 0.46, 0.98, 2.1, 4.5 and 9.0 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 25 to 30 liter glass aquaria, covered to reduce evaporation
- Fill volume: 20 liters
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Aeration: test vessels were aerated via narrow bore glass tubes
- Renewal rate of test solution: daily
- Biomass loading rate: 0.39 g bodyweight/liter (static volume)

TEST MEDIUM / WATER PARAMETERS
- Test water: Laboratory tap water was dechlorinated by passage through an activated carbon filter (Purite Series 500) and partly softened (Elga Nimbus 1248D Duplex Water Softener) giving water with a total hardness of approximately 140 mg/L as CaCO3. After dechlorination and softening the water was passed through a series of computer controlled plate heat exchangers to achieve the required temperature.
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours light and 8 hours darkness with 20 minute dawn and dusk transition periods

EFFECT PARAMETERS MEASURED:
Any mortalities and sub-lethal effects of exposure were recorded at 1, 3, 6, 24, 48, 72 and 96 hours after the start of exposure. The criteria of death were taken to be the absence of both respiratory movement and response to physical stimulation.

PHYSICO-CHEMICAL PARAMETERS MEASURED
The water temperature, pH and dissolved oxygen concentrations were recorded daily throughout the test. The measurements at 0 hours, and after each test media renewal at 24, 48 and 72 hours, represent those of the freshly prepared test preparations while the measurements taken prior to each test media renewal, and on termination of the test after 96 hours, represent those of the used or 24-Hour old test preparations.

TEST CONCENTRATIONS
- Treshold Test: See 'Any other information on materials and methods incl. tables'
- Range finding study: A treshold study at 14% v/v saturated solution and a range finding study at 0.10 and 1.0% v/v saturated solution were performed (100% satured solution prepared of 100 mg test substance/L)
- Results used to determine the conditions for the definitive study: The 14% v/v saturated solution concentration (treshold test) was observed to have 100% mortality at approximately 21 hours. No mortality was observed in the range finding study (0.10 and 1.0% v/v saturated solution) for the complete 96h exposure period.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

5.2 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% C.L.: 4.0 - 6.6 mg/L

Remarks:

Semi-static exposure

Details on results:

MORTALITY
No mortality occurred up to a test concentration of 2.1 mg/L (3.125% v/v saturated solution). At the test concentration of 4.5 mg/L (6.25% v/v saturated solution) 1 fish was dead after 72 hours exposure and 2 fish were dead after 96 hours of exposure (29% mortality). At the highest tested concentration all fish had died within 24 hours exposure. See 'Any other information on results incl. tables'.

GENERAL SYMPTOMS OF TOXICITY
Sub-lethal effects of exposure were observed at test concentrations of 2.1 mg/L (3.125% v/v saturated solution) and above. These responses were increased pigmentation, loss of equilibrium, increased respiratory rate and swimming at the surface.

TEST MEDIUM
The test item preparations were observed to be clear colorless solutions throughout the test.

Reported statistics and error estimates:

An estimate of the LC50 values at 1, 3 and 6 hours were given by inspection of the mortality data. The LC50 values and associated confidence limits at 24, 48, 72 and 96 hours were calculated by the Spearman-Karber method using the ToxRat computer software package (ToxRat, 2015). Summary statistics were based on the average geometric mean measured test concentrations.

Sublethal observations / clinical signs:

Table: Cumulative mortality

Nominal Concentrationin mg/l (% v/v Saturated Solution)	Cumulative Mortality (Initial Population = 7)							% Mortality
	1 Hours	3 Hours	6 Hours	24 Hours	48 Hours	72 Hours	96 Hours	96 Hours
Control	0	0	0	0	0	0	0	0
0.78 (0.46)#	0	0	0	0	0	0	0	0
1.56 (0.98)	0	0	0	0	0	0	0	0
3.125 (2.1)	0	0	0	0	0	0	0	0
6.25 (4.5)	0	0	0	0	0	1	2	29
12.50 (9.0)	0	0	0	7	7	7	7	100

(#the average measured concentration is between brackets)

Table: Sublethal effects

Nominal Concentration in mg/l (% v/v Saturated Solution)	Sub-lethal Effects	Time (Hours)
		1	3	6	24	48	72	96
Control	No abnormalities detected	7	7	7	7	7	7	7
0.78 (0.46)#	No abnormalities detected	7	7	7	7	7	7	7
1.56 (0.98)	No abnormalities detected	7	7	7	7	7	7	7
3.125 (2.1)	No abnormalities detected	7	7	7	7	7	7	4
	Increased pigmentation	0	0	0	0	0	0	3
6.25 (4.5)	No abnormalities detected	7	7	7	0	0	0	0
	Increased pigmentation	0	0	0	7	6	6	5
	Increased pigmentation with loss of equilibrium	0	0	0	0	1	0	0
12.5 (9.0)	Increased respiratory rate	7	0	0	A/D	A/D	A/D	A/D
	Increased respiratory rate, swimming at surface and increased pigmentation	0	7	7	A/D	A/D	A/D	A/D

# (actual measured concentratin in brackets); A/D = All fish dead

Table: Summary statistics

Time Point (Hours)	LC50 (mg/L)	95% Confidence limits (mg/L)
1	> 9.0	Not determined*
3	> 9.0	Not determined*
6	> 9.0	Not determined*
24	6.4	Not determined*
48	6.4	Not determined*
72	5.7	4.7 - 7.0
96	5.2	4.0 - 6.6

* Not determined due to mathematical reasons

Validity criteria fulfilled:

yes

Remarks:

see 'Any other information on materials and methods incl. tables'

Conclusions:

The 96-h LC50 value is 5.2 mg/L in rainbow trout (Oncorhynchus mykiss) based on mean measured concentrations.

Executive summary:

The short-term toxicity to freshwater fish was determined in a study according to OECD TG 203. In this study, groups of 7 rainbow trout (O. mykiss) were exposed to nominal test substance concentrations of 0 (control),0.78, 1.56, 3.125, 6.25 and 12.5% v/v saturated solutionfor 96 hours under semi-static conditions (test medium renewal every 24 hours). The test item solution was prepared by stirring an excess (100 mg/L) of test item in test water 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 µm Sartorius Sartopore filter, first approximate 1 liter discarded in order to pre-condition the filter) to produce a 100% v/v saturated solution of the test item. This saturated solution was further diluted to as necessary to provide the required test concentrations. Analysis of the freshly prepared test media at 0 and 72 hours showed measured test concentrations to range from 0.520 to 10.8 mg/L. There was a >20% decline in the measured concentrations in the aged test media at 24 and 96 hours to between 0.371 and 7.48 mg/L, and hence the results are based on the geometric mean measured test concentrations.The average geometric mean measured test concentrations were determined to be: 0 (control), 0.46, 0.98, 2.1, 4.5 and 9.0 mg/L. Incidences of mortality and clinical effects were recorded after 1, 3, 6, 24, 48, 72 and 96 hours exposure. Clinical effects were first seen after 96 hours exposure at 2.1 mg/L, after 24 hours exposure at 2.1 mg/L and after 3 hours exposure at 9.0 mg/L and generally consisted of increased pigmentation, loss of equilibrium, increased respiratory rate and swimming at the surface. No mortality occurred up to a test concentration of 2.1 mg/L. At the test concentration of 4.5 mg/L 1 fish was dead after 72 hours exposure and 2 fish were dead after 96 hours of exposure (29% mortality). At the highest tested concentration all fish had died within 24 hours exposure. Based on these findings the 96-h LC50 is determined at 5.2 mg/L.

Description of key information

The short-term toxicity to freshwater fish was determined in a study according to OECD TG 203. In this study, groups of 7 rainbow trout (O. mykiss) were exposed to nominal test substance concentrations of 0 (control),0.78, 1.56, 3.125, 6.25 and 12.5% v/v saturated solutionfor 96 hours under semi-static conditions(test medium renewal every 24 hours). The test item solution was prepared by stirring an excess (100 mg/L) of test item in test water 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 µm Sartorius Sartopore filter, first approximate 1 liter discarded in order to pre-condition the filter) to produce a 100% v/v saturated solution of the test item. This saturated solution was further diluted to as necessary to provide the required test concentrations. Analysis of the freshly prepared test media at 0 and 72 hours showed measured test concentrations to range from 0.520 to 10.8 mg/L. There was a >20% decline in the measured concentrations in the aged test media at 24 and 96 hours to between 0.371 and 7.48 mg/L, and hence the results are based on the geometric mean measured test concentrations.The average geometric mean measured test concentrations were determined to be: 0 (control), 0.46, 0.98, 2.1, 4.5 and 9.0 mg/L.Incidences of mortality and clinical effects were recorded after 1, 3, 6, 24, 48, 72 and 96 hours exposure. Clinical effects were first seen after 96 hours exposure at 2.1 mg/L, after 24 hours exposure at 2.1 mg/L and after 3 hours exposure at 9.0 mg/L and generally consisted o fincreased pigmentation, loss of equilibrium, increased respiratory rate and swimming at the surface.No mortality occurred up to a test concentration of 2.1 mg/L. At the test concentration of 4.5 mg/L 1 fish was dead after 72 hours exposure and 2 fish were dead after 96 hours of exposure (29% mortality). At the highest tested concentration all fish had died within 24 hours exposure. Based on these findings the 96-h LC50 is determined at 5.2 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

5.2 mg/L