3,5-xylidine

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to fish, other

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24.12.1997 - 31.03.1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study on behalf of competent authorities of Japan

Qualifier:

according to guideline

Guideline:

OECD Guideline 204 (Fish, Prolonged Toxicity Test: 14-day Study)

Version / remarks:

1984

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
Stock solutions of 0.23, 0.70, 2.20, and 6.90 g of the test substance were prepared in 5,000 mL of pure water (test substance concentration: 46, 140, 440, and 1380 mg/L).

Test organisms (species):

Oryzias latipes

Details on test organisms:

TEST ORGANISM
- Common name: Killifish
- Source: Sankyo Suisan Corporation (Tokyo)
- Length at study initiation (length definition, mean, range and SD): 1.94 cm (1.70 - 2.26 cm), n=10
- Weight at study initiation (mean and range, SD): 0.130 g (0.086-0.223 g), n=10
- Feeding during test
- Food type: commercial Tetramin O
- Amount: 2% of fish weight. When the number of individuals decreased due to mortality, the amount of food fed was reduced accordingly, but not due to a decrease in food intake
- Frequency: daily

ACCLIMATION
- Acclimation period: Jan 22, 1998 - Feb. 10, 1998
- Acclimation conditions: same as test
- Type and amount of food: commercial Tetramin O
- Feeding frequency during acclimation: no feeding 24h prior to start of exposure
- Health during acclimation (any mortality observed): Mortality was less than 5% during the 7 days prior to exposure.

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

14 d

Hardness:

63 mg/L as CaCO3

Test temperature:

24±2 ℃

pH:

7.8

Conductivity:

180 μS/cm

Nominal and measured concentrations:

control, 1.00, 3.04, 9.57 and 30.0 mg/L (ratio 3.1), measured

Details on test conditions:

TEST SYSTEM
- Test vessel: water tank
- Size of vessel: 5L beaker
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: 5L, glass, siphon
- Aeration: none
- Type of flow-through: continuous dilution device with a metering pump
- Renewal rate of test solution (frequency/flow rate): The dilution water was supplied at a flow rate of 22.5 mL/min and the stock solution at 0.5 mL/min by the metering pump. The total flow rate was 23.0 mL/min, and the water replacement rate in the test tank was approximately 7 times/day.
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: pure water


OTHER TEST CONDITIONS
- Adjustment of pH:
- Photoperiod: 16h light, 8h dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
After the start of exposure, the water temperature, dissolved oxygen concentration, and pH of the test solution in each test tank were measured three times a week. fter the start of exposure, the number of deaths was recorded three times a week, and any signs of toxicity or abnormality observed were recorded

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3.1


RANGE-FINDING STUDY from acute toxicity study
- Results used to determine the conditions for the definitive study: LC50(96h) 33.9 mg/L

Reference substance (positive control):

yes

Remarks:

Copper sulfate (II) pentahydrate LC50(96h) 0.73 mg/L (95% confidence interval 0.53 - 1.0 mg/L)

Duration:

14 d

Dose descriptor:

LC50

Effect conc.:

28.5 mg/L

95% CI:

>= 9.04 - <= 28.5

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

0.81 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

not specified

Details on results:

The average value during the test period was 0.81 to 28.5 mg/L. Since there were analytical results that exceeded ±20% of the set concentration, the following values are based on the arithmetic mean of the measured concentrations.

Toxicity Symptoms and Feeding Conditions
Abnormal swimming was observed at a concentration of 28.5 mg/L (set value: 30.0 g/L) as a toxicity symptom. No abnormal symptoms were observed in the control area.
No abnormal symptoms were observed in the control condition.
In addition, a decrease in feeding was observed at concentrations of 2.86 mg/L (set value: 3.04 mg/L) or higher.

Body weight and length of test fish
No significant differences in body weight and length were observed in all concentrations compared to the control.

Reported statistics and error estimates:

LC50 7d and 14d was calculated with Binomial method.

Validity criteria fulfilled:

yes

Conclusions:

The median lethal concentration (LC50) after 14 days was determined to be 28.5 mg/L and the NOEC was determined to be 0.81 mg/L (measured).

Description of key information

OECD 204, GLP, flow-through, fresh-water, Oryzias latipes, 14 d: LC50(14d) 28.5 mg/L and NOEC (14d) 0.81 mg/L

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

NOEC

Effect concentration:

0.81 mg/L