Hydrocarbons, C10-C13, 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.

Reason / purpose for cross-reference:

reference to same 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.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
Water accomodated fractions of Shellsol H were produced by stirring water appropriate to the test organisms and Shellsol H for 45 hours, leaving the contents of the vessel to stand at least for 1 hour and running off the aqueous phase for use as the test medium.

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:

156-190 mg/l CaCO3

Test temperature:

19-20°C

pH:

7.9-8.5

Dissolved oxygen:

8.4-10.8

Salinity:

Not applicable (freswater test)

Nominal and measured concentrations:

Nominal loading rate: 0, 10, 22, 46, 100, 220, 460, 1000 g/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 with WAF or dilution water (control)
- 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: The water comes from two pumping stations (Highstead and controlled by the Mid Kent Water Company. The water is obtained from bore holes in the chalk of the North Downs. The only chemical treatment prior to its arrival in the laboratory is chlorination to 0.1 mg/l. In the laboratory, the water is filtered (PAL MDY 1001 Y400) to remove all particles larger than 15 µm (90% of particles greater than 10µm) and passed through activated carbon filters (Cuno model CT) to remove chlorine and organic conatminants. Both particle and activated carbon filter cartridges are renewed as recommended by the manufacturers. Heat exchange units (stainless steel and perspex) are used to adjust the temperature of the water.
- Intervals of water quality measurement: six months


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

.

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

100 - 220 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EL50

Effect conc.:

460 - 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: None

Validity criteria fulfilled:

yes

Conclusions:

The 48-hr EL50 range for an invertebrate, Daphnia magna, was 100-220 mg/L (WAF).

Executive summary:

The acute toxicity of water accomodated fractions (aqueous extrats) of Shellsol H has been determined to the crustacean zzoplakter Daphnia magna.

The test media were prepared by adding quantities of Shellsol H to culture medium appropriate to the test organisms and stirring in sealed vessels for 45 hours. The strirring period was demonstrated as being sufficient to ensure equilibration of the shellsol H and aqueous phases. After stirring the contents of the test vessels were left to settle for about 1 hour before drawing off the WAF for use as the test media in the toxicity tests.

The concentrations of dissolved hydrocarbons (derived from the shellsol H) in the test media was determined during the toxicit tests usig gas chromatography. The analyses showed that the concentration in the test media was <1%% of the loading rate. The reduction in the concentration of dissolved hydrocarbons in the test media during the test was ≤26%.

The acute toxicity to D. magna of water accomodated fractions of Shellsol H prepared at loading rates ranging from 10 to 1000 mg/l was determined in a 48 static toxicity test without renewal of the test media. The test was conducted in sealed test vessels. The 24 and 48 h EL50 values (loading rates resulting in mortality of 50% of the D. magna after 24 and 48 h exposure) were 460-1000 and 100 -220 mg/l respectively.

Description of key information

There is data available for this substance, which is presented in the dossier.

Hydrocarbons, C10-C13, n-alkanes, isoalkanes, cyclics, aromatics (2-25%) presented a 48-h LC50 (mortality) range for Daphnia magna of 100 -220 mg/L (based on water accommodated fractions).

Additional information

The study from Shell (1995) examined the toxicity of Shellsol H (Hydrocarbons, C10-C13, n-alkanes, isoalkanes, cyclics, aromatics (2-25%)) to the aquatic invertebrate Daphnia magna. The test media were prepared by adding quantities of Shellsol H to culture medium appropriate to the test organisms and stirring in sealed vessels for 45 hours. The strirring period was demonstrated as being sufficient to ensure equilibration of the shellsol H and aqueous phases. After stirring the contents of the test vessels were left to settle for about 1 hour before drawing off the WAF for use as the test media in the toxicity tests. The concentrations of dissolved hydrocarbons (derived from the shellsol H) in the test media was determined during the toxicit tests usig gas chromatography. The analyses showed that the concentration in the test media was <1% of the loading rate. The reduction in the concentration of dissolved hydrocarbons in the test media during the test was ≤26%. The acute toxicity to D. magna of water accomodated fractions of Shellsol H prepared at loading rates ranging from 10 to 1000 mg/l was determined in a 48 static toxicity test without renewal of the test media. The test was conducted in sealed test vessels. The 24 and 48 h EL50 values (loading rates resulting in mortality of 50% of the D. magna after 24 and 48 h exposure) were 460-1000 and 100 -220 mg/l respectively.