Hydrocarbons, C12-C16, n-alkanes, isoalkanes, cyclics, aromatics (2-25%)

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

19-Mar-2003 to 9-Apr-2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The study was given a reliability rating of 1 because it followed a standard test guideline, which describes a procedure to evaluate this endpoint, and the results were reviewed for reliability and assessed as valid. The study was also conducted under GLP.

Justification for type of information:

Hydrocarbons, C12-C16, n-alkanes, isoalkanes, cyclics, aromatics (2-25%) straddles Hydrocarbons, C9-C14, Aliphatics, (2-25% Aromatics) and Hydrocarbons, C14-C20, Aliphatics (2-30% Aromatics). Read across justification documents have been provided for the same in Section 13 of the dossier. For this substance, a worst case scenario approach has been used for each endpoint.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Principles of method if other than guideline:

Followed Part 2 of OECD 202 test guideline.

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Samples were removed from the Control and test concentrations 1000, 2500, 5000, and 10000 mg/l at test initiation (0-hours) and at 48-hours of the preliminary test. Samples were also removed from the control and 2500 and 5000 mg/l concentrations on Day 0, 7, 14, and 20 of the main study. Samples were stored at -18deg C until analysis.

Vehicle:

no

Details on test solutions:

Test solutions were prepared as Water Accommodated Fractions (WAF). The test substance was added to daphnia media, and stirred for 23 hours with a magnetic stirrer until equilibrium. The mixing was done at a slow enough speed as to not cause dispersion or emulsification of the undissolved test substance. The solution was allowed to stand for approximately 1 hour, to allow phase separation, before being carefully siphoned out via a glass tube (added prior to the addition of the test substance). Renewal of the test WAF was conducted every 48 hours.

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia magna - Clone 5 (Crustacea, Daphniidae)
Origin - German Environmental Ministry
Pre-treatment - the animals are cultivated in a climate controlled room
(light/dark = 14h / 10h; illumination: GroLux fluorescent tubes).
The animals were fed with algae (Desmodesmus subspicatus).

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Test temperature:

19.7 to 20.8 deg C

pH:

8.0 to 8.2

Dissolved oxygen:

8.3 to 8.8 mg/l

Salinity:

freshwater

Nominal and measured concentrations:

Nominal concentrations were: 0, 2500, 5000 mg/l.

Concentration analysis (TOC) of the control and 2500 and 5000 mg/l test concentrations gave results of <10 mg/l. Indicating very low solubility of the test substance.

Details on test conditions:

40 animals/conc. (10 each per 4 replicates)
400 ml of solution in 800 ml glass beakers.
14h light / 10h dark - GroLux fluorescent tubes.
Animals were fed daily with algae (Desmodesmus subspicatus)

Reference substance (positive control):

no

Duration:

21 d

Dose descriptor:

EL50

Effect conc.:

> 5 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

immobilisation

Remarks:

Parental generation

Duration:

21 d

Dose descriptor:

EL50

Effect conc.:

< 2 500 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

NOELR

Effect conc.:

< 2 500 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Key result

Duration:

21 d

Dose descriptor:

EL50

Effect conc.:

ca. 1 400 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: inhibition of reproduction

Key result

Duration:

21 d

Dose descriptor:

NOELR

Effect conc.:

ca. 17 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: inhibition of reproduction

Details on results:

Immobilisation of Parental Generation: (at end of test)
Control - 10%
2500 mg/l - 20%
5000 mg/l - 28%

Date of first appearance of young (F1):
Control - 8d
2500 mg/l - 10d
5000 mg/l - 12d

Number of living young produced (at end of test):
Control - 712
2500 mg/l - 265 (62.8% inhibition of reproduction vs. control)
5000 mg/l - 177 (75.1% inhibition of reproduction vs. control)

Number of dead young produced (at end of test):
Control - 10
2500 mg/l - 16
5000 mg/l - 27

Reported statistics and error estimates:

Graphic evaluation on probability paper gave approximate results of the inhibition of reproduction.

Validity criteria fulfilled:

yes

Conclusions:

The chronic toxicity of Hydrocarbons, C11 -C20, n-alkanes, isoalkanes, cyclics, aromatics (2 -30%) as measured by reproductive success to the water flea (Daphnia magna) was evaluated in freshwater. Hydrocarbons, C11 -C20, n-alkanes, isoalkanes, cyclics, aromatics (2 -30%) showed toxic effects as a Water Accommodated Fraction (WAF) with a 21 -day EL50 of approximately 1400 mg/l and an NOELR of 17 mg/l (based on inhibition of reproduction).

Executive summary:

The chronic toxicity of Hydrocarbons, C11 -C20, n-alkanes, isoalkanes, cyclics, aromatics (2 -30%) as measured by reproductive success to the water flea (Daphnia magna) was evaluated in freshwater. Hydrocarbons, C11 -C20, n-alkanes, isoalkanes, cyclics, aromatics (2 -30%) showed toxic effects as a Water Accommodated Fraction (WAF) with a 21 -day EL50 of approximately 1400 mg/l and an NOELR of 17 mg/l (based on inhibition of reproduction).

Description of key information

There is no data available for this substance. However, key data is available for the structural analogue Hydrocarbons, C11-C20, n-alkanes, Isoalkanes, cyclics, 2 -30% aromatics. The data for this substance is presented in this dossier. The data is read across to these substances based on analogue read across and a discussion and report on the read across strategy is provided as an attachment in IUCLID Section 13.

Hydrocarbons, C11-C20, n-alkanes, isoalkanes, cyclics, aromatics (2-30%) did not cause toxicity in a 21-day toxicity study with Daphnia magna following standard test guidelines at a nominal loading of 1400 mg/L, with a NOELR of 17 mg/L (based on inhibition of reproduction). These results indicate that hydrocarbons, C11-C20, n-alkanes, isoalkanes, cyclics, aromatics (2-30%) is not expected to be chronically toxic to freshwater invertebrates.