1,3-di-o-tolylguanidine

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:

2003

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

pH values on the concentrations containing test substance (7.5-8.9) were higher than that on the control and the solvent control (7.5-8.0). These higher pH values were attributed to the presence of the test substance, but these were acceptable range to test organisms. pH of test solutions were not adjusted during the period. no data is available concerning the air saturation value throughout the test.

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

0.75mL of the test solution was sampled from each test container at the start of exposure and after 24 hours (before replacing the water). After adding and mixing an equivalent amount of acetonitrile, HPLC analysis was conducted. The test substance concentration for each test solution was quantified from the ratio to the peak area of the standard solution.

Vehicle:

yes

Details on test solutions:

The dilution water used for preparing the test solution was 24±1°C in the constant temperature tank prior to preparation. The test substance concentrate-1, and test substance concentrate-2 was prepared as follows.


Test substance concentrate -1:

Amount of test substance sampled: 2500 mg
Constant solution: Dimethylformamide
Constant volume: 10 mL
Dissolution method: Ultrasonic mechanical dissolution (several seconds)
Test substance concentration: 250 000 mg/L
Preparation Frequency: at the beginning of exposure
Storage conditions: room temperature

Test substance concentrate -2:

Amount of test substance sampled: 125.0 mg (500µL of test substance solution -1 sampled)
Constant solution: Dilution water
Constant volume: 5000 mL
Dissolution method: Ultrasonic mechanical dissolution (10 min)
Test substance concentration: 25 mg/L auxiliary agent (dimethylformamide). concentration 100 µL/L
Preparation Frequency: prepared when water was changed
Storage conditions: not stored


The amount of test substance concentrate-2 was sampled according to each concentration, while the auxiliary agent concentrate was sampled with the auxiliary agent concentration at a fixed level (auxiliary agent concentration: 100µL/L) for all concentrations, to produce 5.0L with the dilution water.

The control group involved only the dilution water, and the auxiliary agent control group contained only the auxiliary agent (auxiliary agent concentration: 100uL/L).

Test organisms (species):

Oryzias latipes

Details on test organisms:

1) Common Name: Himedaka

2) Scientific Name: Oryzias latipes

3) Supplier: In house

4) Date Received: 2002/13/11

5) Lot Number: 02-H-1113B

6) Fish Length: Mean 1.68cm (1.56~1.79cm), n=10

7) Weight: Mean 0.054g (0.031~0.070g), n=10

8) Sensitivity: Lethal concentration 50 (LC50) in a 96 hour period with a standard substance (copper (II) sulfate pentahydrate, analytical grade reagent) = 0.6 mg/L (95% confidence interval: 0.50~0.95mg/L). This value is nearly identical to the LC50 values (since 1995, n=24) shown below for this laboratory.
Mean value ± standard deviation = 0.93 ± 0.29mg/L
Minimum value ~ maximum value = 0.44 ~ 1.5mg/L

9) Age: Approximately 6 months after weaning

10) Acclimation Period: 2003/22/5 ~ 2003/9/6
The mortality rate 7 days prior to starting exposure was less than 5%, and those appearing healthy to the naked eye were used for testing. (The conditions for the 14 day acclimation period prior to starting exposure are shown below.)

11) Acclimation Conditions:
Breeding Water: Dilution water (refer to 3.2)
Breeding Method: Running water method (breeding density: less than 1.0g/L/day)
Water Temperature: 24 ±1°C
Dissolved Oxygen Concentration: 80% or more of the saturated concentration
pH: 6.5 ~ 8.5
Illumination: Room lighting, 16 hours of light (1000 lux or less)/ 8 hours of dark
Type of Food: Tetrabelke, Tetra Burke Company
Quantity of Food Provided: Approximately 2% of the fish weight/day (no food given for 24 hours prior to starting exposure)

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96

Remarks on exposure duration:

h

Test temperature:

23.5 - 24.9°C

pH:

7.5 - 8.9

Dissolved oxygen:

5.7 - 8.5 mg/L

Nominal and measured concentrations:

Nominal: 5.00, 7.50, 11.0, 17.0, 25.0 mg/L
Measured: 5.03, 7.56, 11.1, 17.4, 25.4 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beaker
- Type (delete if not applicable): covererd with a teflon sheet
- Material, size, headspace, fill volume: 5.0 L
- Renewal rate of test solution (frequency/flow rate): every 24 hours
- 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): 1
- Biomass loading rate: 1.0g per 1.0L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: distilled water
- Intervals of water quality measurement: once per day, before and after the water was replaced

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours light, 8 hours dark
- Light intensity: 1000 luw or less

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : mortality and abnormal swimming

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.5

- Range finding study
- Test concentrations: 2.50, 7.90, 25.0 mg/L
- Results used to determine the conditions for the definitive study: 0, 0, 100%

Reference substance (positive control):

yes

Remarks:

see "details on test organisms"

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

7.56 mg/L

Nominal / measured:

meas. (geom. mean)

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

19.3 mg/L

Nominal / measured:

meas. (geom. mean)

Basis for effect:

mortality (fish)

Remarks on result:

other: (16.6 - 23.4)

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

25.4 mg/L

Nominal / measured:

meas. (geom. mean)

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: abnormal swimming, paralyzation and gill hemorrhage observed at concentration 17.4 mg/L (100% of fish)
- Mortality of control: 0%

Results with reference substance (positive control):

see "details on test organisms"

Validity criteria fulfilled:

yes

Conclusions:

The acute toxicity of DOTG was evaluated with Oryzias latipes in a study performed in accordance with OECD testing guideline 203 and GLP requirements.
LC50-96 h was estimated using measured concentrations as being equal to 19.3 mg/L (16.6 - 23.4).

Executive summary:

 

The acute toxicity of DOTG was evaluated with Oryzias latipes in a study performed in accordance with OECD testing guideline 203 and GLP requirements. The fish were exposed to nominal test concentrations between 5.00 and 25.0 mg/L under semi-static conditions during 96 hours. The mean measured concentrations were maintained between 80 and 120 % of nominal. LC50-96 h was estimated using measured concentrations as being equal to 19.3 mg/L (16.6 - 23.4). Other clinical signs were observed at concentration 17 mg/L: abnormal swimming, paralyzation and gill hemorrhage (100% of fish) Mortality in control, temperatures and pH range were reported and in agreement with the guideline requirements.  The air saturation value of dissolved oxygen concentration is not available, but all value are superior to 5.7 mg/L.

Description of key information

DOTG 96h-LC50 = 19.3 mg/L
Study performed in accordance with:
- OECD testing guideline 203 and
- GLP requirements.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

19.3 mg/L

Additional information

The acute toxicity of DOTG to fish Oryzias latipes was assessed according to the OECD 203 guideline (1992), in a GLP study performed by the Japanese Minstry of Environment.

Water quality parameters of temperature, dissolved oxygen and pH were within acceptable limits. The results of the 96 hour semi-static toxicity study are summarized below:

DOTG 96h-LC50 = 19.3 mg/L (16.6 -23.4 ; measured value). The no effect level observed was 7.56 mg/L after 96 hours.