3,5-xylidine

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Dec.24, 1997 - March 91, 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 202 (Daphnia sp. Acute Immobilisation Test)

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)
The test solution was prepared by diluting 1000 mg of the test substance in 1000 mL of pure water (concentration of test substance: 1000 mg/L). For the test solution, the following volume of the test substance stock solution was taken and diluted to 5.0 g/L with dilution water.
A stock solution containing 100 mg/ml of the test substance was prepared. After adding the test substance stock solution according to each concentration, each test solution was prepared.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Age at study initiation (mean and range, SD): juvenile daphnia within 24 hours of birth
- Stage and instar at study initiation: juveniles
- Source: National Institute for Environmental Studies on July 18, 1995.
- Breeding density: Juveniles: 35 or 40 / 3L; Adults 35 / 3L
- Feeding
- Food type: Chlorella vulgaris
- Amount: 0.15 mg C per Daphnia magna/day
- Feeding during test: no



METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES, INCLUDING CULTURING CONDITIONS:
Adult females of sufficient size to be visually healthy with juvenile Daphnia magna were selected from those in the passages and transferred to a separately prepared beaker.
The next day, the produced larvae were divided into another beaker. The next day, the produced juveniles were divided into another beaker.
At the beginning of the fourth week, on the day before the start of exposure, the larvae were removed at least twice a week.
On the day before the start of the fourth week of exposure, adult females with juveniles in the broodstock were selected from batches that had not produced dormant eggs or males and had less than 5% mortality in the previous two weeks.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

63 mg/L (CaCO3)

Test temperature:

　20±1 ℃

pH:

8.1

Nominal and measured concentrations:

control, 1.00, 1.30, 1.70, 2.30, 3.00, 5.50, 13.0 and 30.0 mg/L (ratio 1.3 - 2.4)

Details on test conditions:

TEST SYSTEM
- Test vessel: Test container
- Type (delete if not applicable): closed with Teflon sheet
- Material, size, headspace, fill volume: glass, 100 mL
- Volume of solution: 100 ml test solution
- No. of organisms per vessel: 5 (20 per concentration)
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4


OTHER TEST CONDITIONS
- Adjustment of pH:
- Photoperiod: 16h light/8h dark
- Light intensity: 1200 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :


RANGE-FINDING STUDY
two preliminary tests
- Test concentrations: 0.1, 1.00, 10.0, 30.0, 100 mg/L and 1.00, 3.00, 10.0 , 30.0 and 100 mg/L

Reference substance (positive control):

yes

Remarks:

potassium dichromate The EiC50 was 0.23 mg/kg for 48 hours.

Duration:

48 h

Dose descriptor:

LC100

Effect conc.:

5.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

1.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

2.2 mg/L

95% CI:

>= 2.02 - <= 2.4

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Since all measured concentrations of the test substance were within ±20% of the set value, the set value was used for the calculation of each effect concentration.
No Daphnia magna was observed floating on the surface of the water in the control area.

Reported statistics and error estimates:

The swimming inhibition rate (%) was calculated from the number of Daphnia magna swimming inhibition in each concentration zone and the number of individuals tested (20), and the half swimming inhibition concentration (Eic50) was calculated by the Probit method.

Validity criteria fulfilled:

yes

Conclusions:

The median immobilisation concentration (EC50) after 48 hours was determined to be 2.2 mg/L.

Executive summary:

A GLP- acute immobilization test (static) of 3,5-xylidine on Daphnia magna in a 48-hour exposure was carried out in accordance with the acute immobilization test described in "Methods of Tests pertaining to New chemical Substances, Etc" and comparable to OECD Guideline 202.

20 daphnids per concentration area (5 daphnids/ container) were exposed to the test substance at static conditions and at test concentrations of 0.1, 1.00, 10.0, 30.0, 100 mg/L and 1.00, 3.00, 10.0 , 30.0 and 100 mg/L (nominal). The median immobilisation concentration (EC50) after 48 hours was determined to be 2.2 mg/L and the NOEC was determined to be 1.3 mg/L.

Description of key information

OECD 202, GLP, Daphnia magna, static: EC50(48h) 2.2 mg/L (nominal)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

2.2 mg/L