2-methyldecan-1-al

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17 September 2014 to 30 October 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study was conducted in accordance with international guidelines and in accordance with GLP. All relevant validity criteria were met.

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Refer to Section 13.2 for the read-across justification document

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

17 July 1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Nominal concentrations of 100, 45.9, 21.0, 9.65, 4.43 and 2.03 mg/L, including control
- Sampling method: In the range finding study and definitive study, at initiation of exposure (0 hour), and at 24, 48, 72 (before and after renewal of test solution) and 96 hours after exposure, the samples were collected three times from the mid-layer of each test chamber in the treatment groups and control group, and analyzed.
- Sample storage conditions before analysis: No storage of samples reported

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: For the definitive study, a saturated solution with a loading rate of 100 mg/L was prepared and dilutions at dilution ratios of 1:2.18, 1:4.75, 1:10.36, 1:22.59, 1:49.23 (at nominal concentrations of 45.9, 21.0, 9.65, 4.43, 2.03 mg/L) from the saturated solution were prepared by serial dilution in accordance with the result of the range finding study.
Saturated solution preparation: The required amount of the test substance was weighed (no correction for % active ingredient) and mixed with breeding water and the bottle was filled completely and tightly closed. This preparation was sonicated by sonication for 15 minutes and intense stirring using a magnetic stirrer for 3 hours in the dark and then, filtered through a 0.7 μm glass fiber filter.
Five liters of the test solution were prepared for each treatment group and the control group was prepared only with breeding water. The control and test solutions were prepared on the day of exposure.
- Eluate: Municipal drinking water from Cheongju was filtered and irradiated by ultraviolet light and used as breeding water. Samples of breeding water are analyzed for microorganisms once a month and for environmental contaminants twice a year by the Research Institute of Health & Environment, ChungBuk (184, Osong saengmyeong1(il)-ro, Osong-eup, Heungdeok-gu, Cheongju-si, Chungcheongbuk-do, REPUBLIC OF KOREA) according to the Regulation of Quality Criteria for Potable Water and Test (Ministry of Environment Ordinance No. 439, Revision Dec. 30, 2011). The results were confirmed to meet the allowable standard of this facility.
- Differential loading: Not applicable, prepared by serial dilution.
- Controls: Blank control (wluate only)
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Not applicable
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): Not applicable
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): None reported

Test organisms (species):

Oryzias latipes

Details on test organisms:

TEST ORGANISM
- Common name: Ricefish
- Strain: Not reported
- Source: Ricefish were obtained from National Institute of Environmental Research (42, Hwangyeong-ro, Seo-gu, Incheon, Korea) on May 14, 2007
- Age at study initiation (mean and range, SD): Not reported
- Length at study initiation (length definition, mean, range and SD): 1.94±0.12 cm (mean±SD, minimum: 1.76 cm, maximum: 2.18 cm)
- Weight at study initiation (mean and range, SD): 0.19±0.01 g (mean±SD, minimum: 0.184 g, maximum: 0.202 g)
- Method of breeding: Upon receipt, suitable male and female fish, at a ratio of 3 to 2 without any visible abnormalities and of similar size were selected and placed in breeding water of 50 L. Approximately 25 fish (±10%) were bred.
Eggs were harvested in breeding chambers and placed in hatching chambers. After hatching, the fry were placed in breeding chambers maintained at 23±1°C and bred.
- Maintenance of the brood fish: Approximately 30% of holding water was replaced once a week. The holding room was artificially illuminated; 16-hour light and 8-hour dark. Fish were fed Brine Shrimp (Ocean Star International, Inc., U.S.A.) in the morning and Top Meal (Jaeilfeed Co., Korea) in the afternoon, at an amount corresponding to approximately 3% of their body weight daily, except from Saturday afternoon to Sunday, when they were fasted.

ACCLIMATION
- Acclimation period: Prior to initiation, fish without any visible abnormalities and of similar size were acclimated for 10 days in breeding water.
- Acclimation conditions (same as test or not): During the acclimation period, water was maintained at a temperature from 22.0 to 22.1oC in the range finding study and at a temperature from 22.0 to 22.3oC in the definitive study, and a dissolved oxygen concentration was maintained at 96.1–98.8% of the saturation value in the range finding study and at 96.3–98.2% of the saturation value in the definitive study, respectively. The room was artificially illuminated with 16 hours of light and 8 hours of dark cycle.
- Type and amount of food during acclimation: The fish were fed with Brine Shrimp (Ocean Star International, Inc., U.S.A.) in the morning and with Top meal (Jaeilfeed Co., Korea) in the afternoon, at an amount corresponding to approximately 3% of their body weight, once daily except from Saturday afternoon to Sunday when they were fasted.
- Health during acclimation (any mortality observed): The mortality was observed from 48 hours after acclimation. During seven days prior to exposure, the mortality of a batch of fish was less than 5% of the population, thus, a batch of fish was used.

QUARANTINE (wild caught)
Not applicable

FEEDING DURING TEST
Fish were not fed during the test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Remarks on exposure duration:

Standard exposure duration in accordance with OECD 203

Test temperature:

23±1°C

pH:

6.0–8.5

Dissolved oxygen:

at least 60% of the air-saturation value 8.39 mg/L (23°C))

Nominal and measured concentrations:

Nominal concentrations: 100, 45.9, 21.0, 9.65, 4.43 and 2.03 mg/L
Arithmetic mean measured concentrations: 10.08 mg/L, 4.96 mg/L, 2.15 mg/L, 0.9658, 0.4284 mg/L and 0.2104 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass test chamber (5 L beaker)
- Type (delete if not applicable): closed (covered in aluminium foil)
- Aeration: Not reported
- Type of flow-through (e.g. peristaltic or proportional diluter): Not applicable
- Renewal rate of test solution (frequency/flow rate): Semi-static test conditions with replacement of the test solution at 24-hour intervals
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): Not applicable
- Biomass loading rate: Loading ratios of fish did not exceed 1.0 g fish/liter of solution

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Same as holding
- Total organic carbon: Not reported
- Particulate matter: 110 mg/L total solids
- Metals: Acceptable
- Pesticides: Acceptable
- Chlorine: Acceptable
- Alkalinity: Acceptable
- Ca/mg ratio: Acceptable
- Culture medium different from test medium: No
- Intervals of water quality measurement: Annual

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16-hour light and 8-hour dark cycle
- Light intensity: Only "fluorescent lighting" reported

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2.1
- Justification for using less concentrations than requested by guideline: Not applicable
- Range finding study
- Test concentrations: 100, 10 and 1 mg/L
- Results used to determine the conditions for the definitive study: Yes

Reference substance (positive control):

yes

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

1.819 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL (1.318 - 2.600 mg/L)

Details on results:

- Behavioural abnormalities:
- Observations on body length and weight: At 96 hours after exposure, the total size and weight of control fish were 2.01±0.10
cm and 0.20±0.01 g (mean±SD), respectively
- Other biological observations: None reported
- Mortality of control: No
- Other adverse effects control: None
- Abnormal responses: None reported
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No
- Effect concentrations exceeding solubility of substance in test medium: No

During the exposure period, the mortality in the control group was 0% (less than 10% as specified in the OECD No. 203 test guideline). The dissolved oxygen concentrations in the treatment groups and control group were maintained at more than 60% of the air-saturation values. Therefore, the results were considered to be acceptable.

Results with reference substance (positive control):

A positive control 96-hour study using Oryzias latipes for the exposure to Copper (II) Sulfate (Wako Pure Chemical Industries, Ltd.) as a reference material was performed once every six months and the LC50 was determined. The result was 0.30 mg/L, which was within the permissible range of historical data (mean±2SD: 0.25–0.65 mg/L) in this laboratory of Biotoxtech Co., Ltd. Exposure conditions of the positive control study were identical to the conditions of the definitive study.

Reported statistics and error estimates:

Statistical analysis was performed using the U.S. EPA authorized program. During the exposure period, a concentration-mortality curve was generated and the LC50 and its 95% confidence limits for mortality at 24, 48, 72 and 96 hours after exposure were analyzed using an Probit method2) and Moving Average-Angle method.

Sublethal observations / clinical signs:

Table 1. Cumulative Mortality of Fish during the Range Finding Study

			Cumulative Number of Dead Fish (Mortality, %)
Nominal concentration (mg/L)	Arithmetic mean measured concentration (mg/L)	Number of fish tested	1 hr	3 hrs	6 hrs	24 hrs	48 hrs	72 hrs	96 hrs
Control	N.D.	10	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)
2.03	0.2104	10	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)
4.43	0.4284	10	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)
9.65	0.9658	10	0 (0)	0 (0)	0 (0)	0 (0)	1 (10)	1 (10)	1 (10)
21.0	2.150	10	0 (0)	0 (0)	0 (0)	0 (0)	5 (50)	5 (50)	5 (50)
45.9	4.960	10	2 (20)	10 (100)	10 (100)	10 (100)	10 (100)	10 (100)	10 (100)
100	10.08	10	10 (100)	10 (100)	10 (100)	10 (100)	10 (100)	10 (100)	10 (100)

N.D.: Not detected

Validity criteria fulfilled:

yes

Conclusions:

The 96h LC50 was determined to be 1.819 mg/L (95% confidence limits: 1.318–2.600 mg/L) after 96 hours of exposure.

Executive summary:

This study was designed to determine the acute toxicity and the median lethal concentration (LC50) of the test item, in Ricefish, Oryzias latipes, during an exposure period of 96 hours under semi-static test conditions in a closed system. The study was conducted in accordance with OECD 203. Based on the result of the range finding study, the definitive study was conducted and treatment levels were selected at the 1:2.18, 1:4.75, 1:10.36, 1:22.59 and 1:49.23 dilutions (at nominal concentrations of 45.9, 21.0, 9.65, 4.43 and 2.03 mg/L), and a control group was prepared for this study. 10 test organisms were exposed to each test concentration and the control.

During the exposure period, the mortality in the control group was 0% (less than 10% as specified in the OECD No. 203 test guideline). Water quality parameters such as temperature and pH-value were within the acceptable limits. The dissolved oxygen concentrations in the treatment groups and control group were maintained at more than 60% of the air-saturation values. Therefore, the results were considered to be acceptable.

The concentrations of test item were determined via GC-Analysis from freshly prepared media at 0, 24, 48, 72 hours and from the corresponding 24 h old media after 24, 48, 72 and 96 hours. Arithmetic mean measured concentrations were 10.08 mg/L (saturated solution), 4.96 mg/L (1:2.18), 2.15 mg/L (1:4.75), 0.9658 (1:10.36), 0.4284 mg/L (1:22.59) and 0.2104 (1:49.23). The 24 h aged test media were maintained in the range of ±20% when compared to the initially measured concentrations of the freshly prepared media at 0, 24, 48 and 72 hours. Nevertheless, all test results were calculated based on the arithmetic mean measured concentration. The reason for using the arithmetic mean is the possibility that the concentration in the preparation of the test solutions may vary in this study with replacement of the test solution at 24, 48 and 72-hour intervals.

Based on the results of this study, the LC50 obtained under the test conditions with the test item was determined to be 1.819 mg/L (95% confidence limits: 1.304–2.564 mg/L) after 96 hours of exposure.

The highest concentration causing no mortality was determined to be 0.4284 mg/L after 96 hours of exposure. The lowest concentration causing 100% mortality was determined to be 4.960 mg/L after 96 hours of exposure.

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Refer to Section 13.2 for read-across justification document.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

1.819 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95 % CL (1.304 - 2.564 mg/L)

Validity criteria fulfilled:

yes

Remarks:

read-across is considered valid in a one-to-one approach

Conclusions:

The 96h LC50 was determined to be 1.858 mg/L (95% confidence limits: 1.318–2.600 mg/L) after 96 hours of exposure.

Executive summary:

In a one-to-one read-across approach, the substance n-undecanal (source substance) is considered appropriate for direct read-across (one-to-one) to 2 -methyldecanal (target substance) for the endpoint short-term toxicity to fish. In conclusion, the 96h LC50 for the registered substance is considered the same as the source substance = 1.819 mg/L. A full justification for the read-across approach is presented in IUCLID Section 13.2.

Description of key information

96h LC50 = 1.819 mg/L; OECD 203; Anon., 2014 (read-across to n-undecanal)

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

1.819 mg/L

Additional information

A single key study was conducted using read-across to n-undecanal, to determine the acute toxicity and the median lethal concentration (LC50) of the test item, in Ricefish, Oryzias latipes, during an exposure period of 96 hours under semi-static test conditions in a closed system. The study was conducted in accordance with OECD 203. Based on the result of the range finding study, the definitive study was conducted and treatment levels were selected at the 1:2.18, 1:4.75, 1:10.36, 1:22.59 and 1:49.23 dilutions (at nominal concentrations of 45.9, 21.0, 9.65, 4.43 and 2.03 mg/L), and a control group was prepared for this study. 10 test organisms were exposed to each test concentration and the control.

During the exposure period, the mortality in the control group was 0% (less than 10% as specified in the OECD No. 203 test guideline). Water quality parameters such as temperature and pH-value were within the acceptable limits. The dissolved oxygen concentrations in the treatment groups and control group were maintained at more than 60% of the air-saturation values. Therefore, the results were considered to be acceptable.

The concentrations of test item were determined via GC-Analysis from freshly prepared media at 0, 24, 48, 72 hours and from the corresponding 24 h old media after 24, 48, 72 and 96 hours. Arithmetic mean measured concentrations were 10.08 mg/L (saturated solution), 4.96 mg/L (1:2.18), 2.15 mg/L (1:4.75), 0.9658 (1:10.36), 0.4284 mg/L (1:22.59) and 0.2104 (1:49.23). The 24 h aged test media were maintained in the range of ±20% when compared to the initially measured concentrations of the freshly prepared media at 0, 24, 48 and 72 hours. Nevertheless, all test results were calculated based on the arithmetic mean measured concentration. The reason for using the arithmetic mean is the possibility that the concentration in the preparation of the test solutions may vary in this study with replacement of the test solution at 24, 48 and 72-hour intervals.

Based on the results of this study, the LC50 obtained under the test conditions with the test item was determined to be 1.819 mg/L (95% confidence limits: 1.304–2.564 mg/L) after 96 hours of exposure.

The highest concentration causing no mortality was determined to be 0.4284 mg/L after 96 hours of exposure. The lowest concentration causing 100% mortality was determined to be 4.960 mg/L after 96 hours of exposure.