Reaction mass of divinylbenzene and ethylstyrene

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 202, part 2 "Daphnia sp., Reproduction Test"

Deviations:

not applicable

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

The tested concentrations were measured before and after renewal of the test water, 4 times during the test period.

Vehicle:

yes

Details on test solutions:

Vehicle/Solvent and Concentrations: DMF (N,N-Dimethylformamide) and HCO-40 were used as solvents in the tests. The concentrations of DMF and HCO-40 in stock solution were 1000 mg/L each. The total final concentrations of the two solvents for the tests were 20 mg/L.

Stock Solutions Preparations and Stability: The test substance (100 mg) was dissolved in DMF (500 mg), and HCO-40 (500 mg) was added. The amount of the test solution was adjusted to 500 mL by dilution water (test substance 200 mg/L).

Test organisms (species):

Daphnia magna

Details on test organisms:

Test Organisms:
a) Age: < 24 hours old
b) Supplier / Source: National Institute for Environmental Studies (JAPAN)

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Post exposure observation period:

None

Hardness:

Dilution water: 63 mg/L (as CaCO3)

Test temperature:

19.7-20.9°C

pH:

7.1-8.0

Dissolved oxygen:

6.7-8.6 mg/L

Salinity:

No data

Nominal and measured concentrations:

Nominal Concentrations (as mg/L): 0, 0.100, 0.210, 0.450, 0.950 and 2.00
Measured Concentrations (as mg/L): 0.074, 0.152, 0.353, 0.711 and 1.59

Details on test conditions:

Test Conditions:
a) Dilution Water Source: Dechlorinated tap water
b) Dilution Water Chemistry: Hardness (as CaCO3) 63 mg/L, pH 8.1 (22 degrees centigrade), Alkalinity 45 mg/L, Chlorine concentration < 0.01 mg/L
c) Exposure Vessel Type: 80 mL test solution in a 100 mL Glass Beaker covered with Teflon Sheet
d) Nominal Concentrations (as mg/L): 0, 0.100, 0.210, 0.450, 0.950 and 2.00
e) Vehicle/Solvent and Concentrations: DMF (N,N-Dimethylformamide) and HCO-40 were used as solvents in the tests. The concentrations of DMF and HCO-40 in stock solution were 1,000 mg/L each. The total final concentrations of the two solvents for the tests were 20 mg/L.
f) Stock Solutions Preparations and Stability: The test substance (100 mg) was dissolved in DMF (500 mg), and HCO-40 (500 mg) was added. The amount of the test solution was adjusted to 500 mL by dilution water (test substance 200 mg/L).
g) Number of Replicates: 10
h) Individuals per Replicates: 1
i) Renewal Rate of Test Water: 3 times per a week
j) Water Temperature: 19.7 - 20.9°C
k) Light Condition: 16:8 hours, light-darkness cycle, not more than 1200 lux
l) Feeding: 0.15 mg carbon/day/individual (Chlorella Vulgaris)

Reference substance (positive control):

not specified

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.353 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

0.711 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

0.718 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

LC50

Effect conc.:

1.06 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

- Cumulative Number of Dead Parental Daphnia: 21 days; Control (0), 0.100 mg/L (0), 0.210 mg/L (0), 0.450 mg/L (0), 0.950 mg/L (0) and 2.00 mg/L (10)
- Time (days) of the First Production of Young: Control (7 - 8), 0.100 mg/L (7 - 10), 0.210 mg/L (7 - 11), 0.450 mg/L (7 - 8), 0.950 mg/L (8 - 9) and 2.00 mg/L (0)
- Mean Cumulative Number of Young Production per Adult: Control (87.9), 0.100 mg/L (110.8), 0.210 mg/L (114.1), 0.450 mg/L 120.0), 0.950 mg/L (52.8) and 2.00 mg/L (0)
- Calculation of toxic values: Based on the measured concentrations, because some data of the measured concentrations were <80 % of the nominal concentrations

Reported statistics and error estimates:

Data Analysis: Binominal Method for LC50, Logit and Binominal Method for EC50, Dunnette/William Multiple Comparison test for NOEC and LOEC  
Method of Calculating Mean Measured Concentrations (i.e. arithmetic mean, geometric mean, etc.): Time-weighted Mean measured concentration during 21 days

Validity criteria fulfilled:

yes

Conclusions:

The NOEC and LOEC was 0.353 and 0.711 mg/L, respectively. The EC50 and LC50 was 0.718 and 1.06 mg/L, respectively.

Executive summary:

The study was conducted according to OECD Guideline 202, part 2 "Daphnia sp., Reproduction Test". The NOEC and LOEC was 0.353 and 0.711 mg/L, respectively. The EC50 and LC50 was 0.718 and 1.06 mg/L, respectively.

Description of key information

A GLP-study according to OECD guideline 202 Part 2 (Daphnia Reproduction Test) is available for the reaction mass of divinylbenzene and ethylstyrene. The 21-day NOEC (based on reproduction) for DVB-HP (80% divinylbenzene/20% ethylstyrene) was 0.353 mg/L in a chronic exposure with Daphnia magna.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.353 mg/L

Additional information

One high quality (Klimisch rating 1) chronic toxicity study with Daphnia magna was performed using DVB-HP (approximately 80% divinylbenzene and 20% ethylstyrene). The 21-day NOEC (based on reproduction) was 0.353 mg/L. The 21-day LOEC and EC50 (based on reproduction) were 0.711 mg/L and 0.718 mg/L, respectively. The 21-day LC50 was 1.06 mg/L. Since the toxicity of the reaction mass of divinylbenzene/ethystyrene increases with increasing divinylbenzene content (based on data from acute toxicity studies with Daphnia magna and freshwater fish), the NOEC for DVB-HP is expected to be a conservative estimate of toxicity for all other grades of the reaction mass of divinylbenzene and ethystyrene containing less than 80% divinylbenzene.