Coke (coal), naphtha cracking ethylene manuf. by-product

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The test is a 24 hour test, which was recommended when the test was carried out. Since the toxicity is due to low pH, increasing the test duration would not change the test results.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

exposure period 24 h

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Carbon black (Spezialschwarz 4)

IUPAC Name:

Carbon black (Spezialschwarz 4)

Details on test material:

Carbon Black (Spezialschwarz 4). A channel black, insoluble in water, which gives an acidic pH in aqueous suspension.

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

Dilution water used was DSWL prepared from ground water. It has proven to be suitable for the culture of daphnia magna. This medium is prepared by addition of severalsalts to groundwater from a locality near Linschoten (the Netherland.). The groundwater contains several other trace elements
(<< 1 mg/l). The equlibrium pH of the medium, after aeration, should be 8.3-8.5, but is usually slightly less, namely 8.0-8.2. The medium is prepared in large amounts ( 10,000 l) and the following components of the batch used for this test were checked by chemical analysis and found to be:
Na+ 1.20 mmol/l
K+ 0.22 mmol/l
Ca2+ 1.3 mmol/l
Mg2+ 0.74 mmol/l
Cl- 2.71 mmol/l
SO4 2- 0.69 mmol/l
The total organic carbon content was 1.5 mg/l.
Suspensions of the test substance were prepared in dilution water by stirring on a magnetic stirrer for 20 hours at 20 °C. The suspensions were
then filtered through a paper filter (S&S 595 1/2. This filtrate was tested. The test concentrations were the filtrates from 1000, 1800, 3200, 5600
and 10 000 mg/L suspensions. At the beginning of the test all filtered solutions were clear. At the end of the test the solutions were still clear,
though some undissolved material was observed on the bottom of the test vessels.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

The organisms used was the fresh-water crustaceae daphnia magna, cultured in the laboratory under standard conditions, according to the principles of NPR 6503. The animals were less than 24 h old at the beginning of the test

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Post exposure observation period:

no

Test conditions

Hardness:

The hardness, expressed as CaCO3, was 204 mg/l.

Test temperature:

19.4 - 20.0 °C

pH:

at the start and at the end of the test:
control: 8.1 - 8.0
1000 mg/l: 8.1 - 8.0
1800 mg/l: 6.9 - 7.8
3200 mg/l: 6.4 - 7.6
5600 mg/l: 5.6 - 6.7
10.000 mg/l: 4.3 - 4.7

Dissolved oxygen:

at the beginning of the test: 8.6 - 8.9
at the end of the test: 8.0 - 8.9

Salinity:

not applicable

Nominal and measured concentrations:

nominal concentrations

Details on test conditions:

Two range-finding tests were carried out:
A test with dosed amounts of 1000 mg/l and 10 000 mg/l. the test suspensions were stirred vigorously for about 1.5 h on a magnetic stirrer at
20°C. Part of the suspension was then filtered through a paper filter. Both filtered and non-filtered "solutions" were tested. Ten animals were
exposed in 100 ml under the same conditions as given for the final test.
A test with filtered solutions of dosed amounts of 1000; 3200, and 10.000 mg/l. The solutions were prepared as described for the other
range-finding test, however, the suspension was stirred for 24 hours, before filtration. Ten animals were exposed in 100 ml under the conditions given for the final test.
Final test:
The test was carried out under 16 h light-8 h dark regime with transition periods of 30 minutes in a temperature controlled room of 20 +-1°C.
The temperature in one of the control vessels was measured at the beginning and at the end of the test.
The preliminary range-finding tests showed that the daphnias were possibly hampered by undissolved particles and therefore it was decided to
prepare water accomodated fractions of the test substance.
Five concentrations of Spezialschwarz 4 were tested. DSWL was used as a control medium. 1.0, 1.8, 3.2, 5.6, 10 g of the test substance were accurately weighed out and each portion was added to one litre of dilution water, resulting in test suspensions of 1000, 1800, 3200, 5600, and 10.000 mg/l.
These suspensions were vigorously stirred on a magnetic stirrer for 20 h at 20°c. After this period, the suspensions were filtered through a paper
filter (S & S 595 1/2) and the filtrates used as test solutions. DSWL was treated in the same way.
The test was performed in 150 ml all-glass beakers, each containing 100 ml of test solution or control medium. Four beakers containing 5 daphnias
each were used for each test solution or control medium. The test solutions and control media were not aerated or replaced. The daphnias were not
fed. The ph and the oxygen concentration of the test solutions and the control media were measured at the beginning and at the end of the test.
The immobile animals were counted at the end of the test according to the definition given in the OECD Guideline 202. At the same time the conditions (swimming behaviour, colour or any other visually observable morphological or bahavioural criterion) of the mobile animals was visually compared
with that of the control animals. The daphnias from the test solutions of 5600 and 10.000 mg/l were also checked under a microscope.

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

3 200 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 3

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 5 600 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Range finding test:
first test: All daphnias died in the non-filtered suspension of 10,000 mg/l. In the filtered solution five out of ten daphnias died. At a dose amount
of 1000 mg/l all daphnias survived in the filtered solution and two out of ten daphnias died in the non-filtered suspension.
second test: all animals died in the filtered solution of 10,000 mg/l. All other animals suvived exposure.
Final test:
The pH values of the test solutions varied between 4.3 and 8.2. It is very likely that the pH affected the mobility of the daphnias at the dose amount of 10,000 mg/l and it cannot be excluded that this is also the case for the effects on conditions at 5600 mg/l. It is not likely that the oxygen
concentration or the temperature affected the results.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The preliminary range-findin tests showed that the daphias were possibly physically hampered by particles.
Filtrates of suspensions of different concentrations were tested. it is likely that the results were affected by low pH values at 10, 000 and at
5600 mg/l

Executive summary:

Carbon black is not toxic within its aqueous solubility