Hydrocarbons, C9-C12, n-alkanes, isoalkanes, cyclics, aromatics (2-25%)

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:

Sept. 6, 1996-Dec. 9, 1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: all concentrations
- Sample storage conditions before analysis: If samples could not be analysed the day they were taken, they were stored at 4°C and extracted at the earliest opportunity. Samples were stable for up to 7 days.

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Test substance was added to measured volumes of test medium. The vessels were then sealed, leaving a small headspace, and the contents stirred with a 1-2 cm vortex depth until the aqueous and test substance phases equilibrated (45 hrs). The vessels were then allowed to settle for 1-1.5 hrs and the aqueous phase drawn off for use in the test as a Water Accomodated Fraction (WAF). Control media was treated in the same manner.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain: Strauss
- Source: clonal laboratory culture derived from animals obtained from Zeneca Brixham Laboratory
- Age at study initiation (mean and range, SD): less than 24 hrs
- Method of breeding: Cultures started with animals less than 24 hours old, and discarded when 28 days old. Young are removed daily, and animals for testing removed 23 hours after last removal. Test young are from 15-28 day cultures from at least the third brood.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

173 mg/l CaCO3

Test temperature:

19.4-19.7°C

pH:

7.7-7.9

Dissolved oxygen:

8.0-8.7

Nominal and measured concentrations:

Nominal loading rate: 0, 1, 2.2, 4.6, 10, 22, 46, 100 mg/l
Mean concentration of hydrocarbons: <0.05, 0.18, 0.83, 0.85, 1.7, 2.8, 4.7, 7.3 mg/l

Details on test conditions:

TEST SYSTEM
- Test vessel: sealed with a screw cap
- Material, size, headspace, fill volume: 150 ml Erlenmeyer flasks completely filled
- Renewal rate of test solution (frequency/flow rate): static
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reverse osmosis filtered water with the following Analar grade salts added: NaHCO3 192 mg/l, CaSO4.2H2O120 mg/l, MgSO4.7H2O 240 mg/l, KCl 8 mg/l

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : immobilization

TEST CONCENTRATIONS
- Range finding study: Range finding test was conducted similar to the main study except chemical analysis was not done.

Key result

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

10 - 22 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EL50

Effect conc.:

22 - 46 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

other: NOEL

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: None

Number of Immobilized Daphnia magna

Loading Rate (mg/l)	24 hrs	48 hrs
0	0	0
0	0	0
1	0	0
1	0	0
2.2	0	0
2.2	0	0
4.6	0	0
4.6	0	0
10	0	0
10	0	1
22	3	6
22	1	8
46	10	10
46	10	10
100	10	10
100	10	10

Validity criteria fulfilled:

yes

Conclusions:

The 48-hr EL50 range for an invertebrate, Daphnia magna, was 10-22 mg/L (WAF).

Executive summary:

The purpose of this experiment was to determine the acute toxicity of low aromatic white spirits to Daphnia magna. 10 daphnia per test vessel (2 test vessels per concentration) were exposed to loading rates of 0, 1, 2.2, 4.6, 10, 22, 46, or 100 mg/l (WAF) of test substance. The exposure lasted for 48 hrs, and there was no renewal of test solution. At 24 and 48 hrs, the Daphnia were observed for immobilization. Immobilization was seen at test concentrations of 10 mg/l (WAF) and above, with immobilization of all daphnids at the 46 and 100 mg/l concentrations by the 24 hr observation. The 48-hr EL50 range for an invertebrate, Daphnia magna, was 10-22 mg/L (WAF).

Description of key information

There is data available for this substance. Key information is summarized below.

Hydrocarbons C9-C12, n-alkanes, isoalkanes, cyclics, aromatics (2-25%) presented a 48-h EL50 (mobility) range for Daphnia magna of 10 -22 mg/L (based on water accommodated fractions).

Additional information

One study report was available and input as an endpoint record for short term toxicity to aquatic invertebrates.

The study from Shell (1997) examined the short-term toxicity of the test substance Hydrocarbons C9-C12, n-alkanes, isoalkanes, cyclics, aromatics (2-25%) to Daphnia magna. 10 daphnia per test vessel (2 test vessels per concentration) were exposed to loading rates of 0, 1, 2.2, 4.6, 10, 22, 46, or 100 mg/l (WAF) of test substance. Daphnids were exposed for 48h, and there was no renewal of test solution. At 24 and 48 hrs, the Daphnia were observed for immobilization. Immobilization was seen at test concentrations of 10 mg/l (WAF) and above, with immobilization of all daphnids at the 46 and 100 mg/l concentrations by the 24 hr observation. The 48-hr EL50 range for an invertebrate, Daphnia magna, was 10-22 mg/L (WAF).