Hydrocarbons, C11-C12, isoalkanes, <2% aromatics

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

key study

Study period:

January 1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: This robust summary has a reliability rating of 2 because only limited analyses accompanied the study. However, the study generally followed a standard guideline and GLP, and was conducted without deviations that would invalidate the study.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OPPTS 850.1020 (Gammarid Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

The water accommodated fraction prepared at 1000 mg/L and the control used on Day 2 of the study were analyzed. Both samples were analyzed upon preparation and after 24 hours.

Vehicle:

no

Details on test solutions:

Individual treatment solutions were prepared by adding accurately weighed test substance, to 0.5 L of natural seawater in erlenmeyer flasks. The stock solutions were thoroughly mixed for 24 hours and then the phases were allowed to separate for 24 hours. The Water Accommodated Fraction (WAF) was then drawn off the mixing vessel into the test vessels.

Test organisms (species):

other aquatic crustacea: Chaetogammarus marinus

Details on test organisms:

Test organisms were collected in the field in September, 1991 and cultured in the laboratory for 5 months prior to use in the test. They had a mean length of 3.3 mm. During the test, the test organisms were fed a few Artemia nauplii per day.

Test type:

semi-static

Water media type:

saltwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

None

Test temperature:

14.6 to 15.3 degrees C

pH:

7.4 to 7.9

Dissolved oxygen:

Greater than 5.9 mg/L

Salinity:

33.5‰ (3.4%)

Nominal and measured concentrations:

Nominal treatment levels were control, 10, 32, 100, 320, and 1000 mg/L. Measured concentrations for one treatment level and the control were determined for day 2 for the freshly prepared solutions and after 24 hours upon renewal. The 1000 mg/L treatment solution measured 0.096 mg/L when freshly prepared. The 24-hour results were not reported, but characterized as almost non detectable. Results of the control analyses were not reported.

Details on test conditions:

Test vessels were scintillation vials filled with about 20 ml of test solution. Ten replicates of each concentration and control were tested, each containing 1 test organism. The test organisms were gently transferred daily to vials with freshly prepared WAF. Lighting was 16 hrs light and 8 hrs dark.

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

LL50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

LL50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

72 h

Dose descriptor:

LL50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

96 h

Dose descriptor:

LL50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

96 h

Dose descriptor:

NOELR

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

96 h

Dose descriptor:

NOELR

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: swimming behavior and food uptake

Details on results:

Mortality results for the definitive test:
Nominal Crustacean Total
Loading Mortality Mortality
(mg/L) (@ 24, 48, 72, 96 hrs)* (%)
Control 0, 0, 0, 0 0
10 0, 0, 0, 0 0
32 0, 0, 0, 0 0
100 0, 0, 0, 1 10
320 0, 0, 0, 0 0
1000 0, 0, 0, 0 0

* 10 organisms tested at each of the control and treatment treatment levels

Reported statistics and error estimates:

Statistical analyses were not conducted.

Validity criteria fulfilled:

yes

Conclusions:

The water accommodated fraction of the test substance did not produce a 50% effect (mortality) with Chaetogammarus marinus at loadings up to 1000 mg/L after a 96-hour exposure. Therefore, the 96-hour LL50 is reported as >1000 mg/L. There was no mortality at the 1000 mg/L loading level after 96 hours. Therefore, the 96-hour NOELR for mortality is reported as 1000 mg/L. There was also no mortality in the control.

Executive summary:

Water accommodated fractions (WAFs) of the test substance did not produce a 50% effect (mortality) with Chaetogammarus marinus after 96 hours at loadings up to 1000 mg/L. Therefore, the 96-hour LL50 is reported as >1000 mg/L. There was no mortality at the 320 and 1000 mg/L loading levels after 96 hours. However, effects on swimming and feeding behavior were observed in the 320 and 1000 mg/L loading levels. Therefore, the NOELR is reported as 1000 mg/L for mortality and 100 mg/L for the two non lethal effects. Although 10% mortality (1 organism) was observed in the 100 mg/L loading treatment, no mortality was observed in the 320 and 1000 mg/L loading treatments. Because no mortality occurred in the two higher loading levels, the mortality observed in the 100 mg/L was likely not caused by the test material. There was also no mortality in the control during the study. The control and treatment solutions were renewed every 24 hours. Analytical results showed that the treatment solution contained components of the test substance and that their combined concentration represented 0.096 mg/L of the test substance, based on one sample from a freshly prepared WAF for day 2. The 24-hour old sample from day two was reported as almost non detectable. The low analytical results are to be expected because of the very low water solubility of the components of the test substance. The reported 0.096 mg/L is likely to represent the highest achievable concentration of the test substance under the conditions of the test.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

key study

Study period:

May 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This robust summary has a reliability rating of 1 because the study followed a standard guideline, followed GLP guidelines, and was conducted without deviations that would invalidate the study.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The water accommodated fraction (WAF) of the test material was prepared by stirring the test material in the exposure solution for approximately 24 hours. The stirring was as vigorous as possible without causing an emulsion to form. After stirring, the WAF was allowed to settle for 1 hour before removing the aqueous phase for testing.

Test organisms (species):

Daphnia magna

Details on test organisms:

Organisms used in the test were from a laboratory culture were less than 24 hour old. The source of the culture was from Zeneca Brixham Laboratory from I.R.Ch.A., France.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

None

Hardness:

196 mg/L CaCO3

Test temperature:

18 to 20 degrees C

pH:

Within Guideline requirement

Dissolved oxygen:

8.9 to 9.2 mg/L

Nominal and measured concentrations:

The nominal loading rate was 1000 mg/L. A control was also tested.

Details on test conditions:

The study was conducted in closed test systems that were not renewed during the study. The test systems used were 150 ml glass Erlenmeyer flasks. The control and treatment level was evaluated in replicate test systems. Ten organisms, less than 24 hours old, were exposed in each of the control and treatment solution flasks and were not fed during the study.

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

EL50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

LL0

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EL0

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

There was no immobility reported in the treatment and control solutions at test termination.

Reported statistics and error estimates:

None

Validity criteria fulfilled:

yes

Conclusions:

The water accommodated fraction (WAF) of the test substance did not produce a 50% effect (immobility) with Daphnia magna at a loading of 1000 mg/L after a 48-hour exposure. Therefore, the 48-hour LL50 is reported as >1000 mg/L. There was no mortality at the 1000 mg/L loading level after 48 hours. Therefore, the 48-hour LL0 for mortality is reported as 1000 mg/L. There was also no mortality in the control.

Executive summary:

The water accommodated fraction (WAF) of the test substance did not produce a 50% effect (immobility) with Daphnia magna at a loading of 1000 mg/L after a 48-hour exposure. Therefore, the 48-hour LL50 is reported as >1000 mg/L. There was no mortality at the 1000 mg/L loading level after 48 hours. Therefore, the 48-hour LL0 for mortality is reported as 1000 mg/L. There was also no mortality in the control.

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

key study

Study period:

The study was conducted between 04 August 2014 and 08 August 2014.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

Nominal amounts of test item (23 and 230 mg) were each separately added to the surface of 2.3 litres of test water to give the 10 and 100 mg/L loading rates respectively. After the addition of the test item, the test water was stirred by magnetic stirrer using a stirring rate such that a vortex was formed to give a dimple at the water surface. The stirring was stopped after 23 hours and the mixtures allowed to stand for 1 hour. A wide bore glass tube, covered at one end with Nescofilm was submerged into the vessel, sealed end down, to a depth of approximately 5 cm from the bottom of the vessel. A length of Tygon tubing was inserted into the glass tube and pushed through the Nescofilm seal. Microscopic inspection of the WAFs showed no micro-dispersions or undissolved test item to be present. The aqueous phase or WAF was removed by mid-depth siphoning (the first approximate 75-100 mL discarded) to give the 10 and 100 mg/L loading rate WAFs.

Total Organic Carbon (TOC) analysis was performed on the test solutions at 0 and 48 hours.

Test organisms (species):

Daphnia magna

Details on test organisms:

The test was carried out using 1st instar Daphnia magna derived from in-house laboratory cultures.

Adult Daphnia were maintained in 150 mL glass beakers containing Elendt M7 medium in a temperature controlled room at approximately 20 °C. The lighting cycle was controlled to give a 16 hours light and 8 hours darkness cycle with 20 minute dawn and dusk transition periods. Each culture was fed daily with a mixture of algal suspension (Desmodesmus subspicatus) and Tetramin® flake food suspension. Culture conditions ensured that reproduction was by parthenogenesis. Gravid adults were isolated the day before initiation of the test, such that the young daphnids produced overnight were less than 24 hours old. These young were removed from the cultures and used for testing. The diet and diluent water are considered not to contain any contaminant that would affect the integrity or outcome of the study.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Nominal and measured concentrations:

Nominal: 10 and 100 mg/L

Details on test conditions:

Due to the low aqueous solubility and complex nature of the test item, for the purposes of the study the test medium was prepared as a Water Accommodated Fraction (WAF) of the test item.

Previous studies conducted on similar test items (e.g. Harlan Study Number 41304080) indicated that a 23-Hour stirring period followed by a 1-Hour standing period was sufficient to ensure that the maximum dissolved test item concentration was obtained in a Water Accommodated Fraction (WAF), as no significant increase in dissolved carbon was obtained by extending the stirring period to 96 hours.

Definitive Test
The following loading rates were assigned to the definitive test: 10 and 100 mg/L.


Experimental Preparation
Nominal amounts of test item (23 and 230 mg) were each separately added to the surface of
2.3 liters of test water to give the 10 and 100 mg/L loading rates respectively. After the addition of the test item, the test water was stirred by magnetic stirrer using a stirring rate such that a vortex was formed to give a dimple at the water surface. The stirring was stopped after 23 hours and the mixtures allowed to stand for 1 hour. A wide bore glass tube, covered at one end with Nescofilm was submerged into the vessel, sealed end down, to a depth of approximately 5 cm from the bottom of the vessel. A length of Tygon tubing was inserted into the glass tube and pushed through the Nescofilm seal. Microscopic inspection of the WAFs showed no micro-dispersions or undissolved test item to be present. The aqueous phase or WAF was removed by mid-depth siphoning (the first approximate 75-100 mL discarded) to give the 10 and 100 mg/L loading rate WAFs.

Total Organic Carbon (TOC) analysis was performed on the test solutions at 0 and 48 hours.


Exposure Conditions
In the definitive test 100 mL nominal volume conical flasks containing approximately 130 mL of test preparation were used. At the start of the test 5 daphnids were placed in each test and control vessel at random, in the test preparations. Four replicate test and control vessels were prepared. The test vessels were then sealed to reduce loss through volitilization and maintained in a temperature controlled room at approximately 21 °C with a photoperiod of 16 hours light (398 to 481 lux) and 8 hours darkness with 20 minute dawn and dusk transition periods. The daphnids were not individually identified, received no food during exposure and the test vessels were not aerated.

The control group was maintained under identical conditions but not exposed to the test item.

The test preparations were not renewed during the exposure period.

Data from the control group was shared with similar concurrent studies.
Evaluations
Test Organism Observations
Any immobilization or adverse reactions to exposure were recorded at 24 and 48 hours after the start of exposure. The criterion of effect used was that Daphnia were considered to be immobilized if they were unable to swim for approximately 15 seconds after gentle agitation.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: The toxicity cannot be attributed to a single component or a mixture of components, but to the test item as a whole.

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Total Organic Carbon Analysis
Total Organic Carbon (TOC) analysis of the test preparations at 0 and 48 hours showed no significant differences in the amount of carbon present within the 10 and 100 mg/L loading rate WAF test vessels when compared to the control vessels. Therefore, given the background level of carbon in the control vessels and also the low level of carbon in the test vessels, it was considered that all the results were around the limit of quantification of the analytical method.

The dissolved test item may have been one or several components of the test item. Given that toxicity cannot be attributed to a single component or mixture of components but to the test item as a whole, the results were based on nominal loading rates only.

Immobilization Data
There was no significant immobilization in 20 daphnids exposed to concentrations of 10 and 100 mg/L loading rate WAF for a period of 48 hours. Inspection of the immobilization data gave the following results:
The 24 h EL50 was > 100 mg/L Loading Rate WAF
The 48 h EL50 was > 100 mg/L Loading Rate WAF

The No Observed Effect Loading rate after 24 and 48 hours exposure was 100 mg/L loading rate WAF.

Validation Criteria
The test was considered to be valid given that none of the control daphnids showed immobilization or other signs of disease or stress and that the oxygen concentration at the end of the test was ≥3 mg/L in the control and test vessels.

Water Quality Criteria
Temperature was maintained at approximately 21 °C throughout the test, while there were no treatment related differences for oxygen concentration or pH.

Vortex Depth Measurements
The vortex depth was recorded at the start and end of the mixing period and was observed to be a dimple at the water surface on each occasion.

Observations on Test Item Solubility
Observations on the test media were carried out during the mixing and testing of the WAFs.

At the start of the mixing period the 10 and 100 mg/L loading rates were observed to be clear colorless water columns with globules of test item at the surface. After 23 hours stirring the 10 and 100 mg/L loading rates were observed to be clear colorless water columns. After a 1-Hour settlement period, the 10 and 100 mg/L loading rates were observed to be clear colorless solutions. Microscopic inspection of the WAFs showed no micro-dispersions or undissolved test item to be present. After siphoning and for the duration of the test, the 10 and 100 mg/L loading rates were observed to be clear, colorless solutions.

Results with reference substance (positive control):

A positive control (Harlan Study Number 41400711) used potassium dichromate as the reference item at concentrations of 0.32, 0.56, 1.0, 1.8 and 3.2 mg/L.

Exposure conditions for the positive control were similar to those in the definitive test.

Analysis of the immobilization data by the maximum-likelihood probit method (Finney, 1971*) at 24 hours and by the trimmed Spearman-Karber method (Hamilton et al 1977**) at 48 hours based on the nominal test concentrations gave the following results:
The 24 h EC50 was 0.87 mg/L with 95% confidence limits of 0.75 - 1.0 mg/L.
The 48 h EC50 was 0.71 mg/L with 95 % confidence limits of 0.65 - 0.78 mg/L.
The NOEC was 0.56 mg/L and the LOEC was 1.0 mg/L.

The No Observed Effect Concentration is based upon less than 10% immobilization at this concentration.

The results from the positive control with potassium dichromate were within the normal range for this reference item.

Reported statistics and error estimates:

An estimate of the EL50 values was given by inspection of the immobilization data.

Validation Criteria

The results of the test are considered valid if the following performance criteria are met:

·        No more than 10% of the controldaphnids show immobilization or other signs of disease or stress (e.g. discoloration or unusual behavior such as trapping at the surface water).

·        The dissolved oxygen concentration at the end of the test is ≥3 mg/L in the control and test vessels.

Validity criteria fulfilled:

yes

Conclusions:

Measured acute (short-term) toxicity data are available for Shell GTL Solvent GS190 (Hydrocarbons, C10-C13, n-alkanes, isoalkanes, <2% aromatics) to the freshwater invertebrate Daphnia magna. The test was conducted under static (no renewal of the test media) conditions in accordance with OECD Test Guideline 202 and method C2 of EC Regulation No. EC 440/2008. Appropriate modifications to the test and media preparation procedures were made to take account of the test substance containing multiple constituents, having low solubility in water and being potentially volatile. No effects on mobility of D. magna were observed after 48 hours exposure to the test medium prepared as a water-accommodated fraction (WAF) at loading rates up to 100 mg/l; 48-hour EL50 >100 mg/l, NOELR ≥100 mg/l. Samples of the control and the 10 and 100 mg/l loading rate WAFs were taken at 0 and 48 hours for Total Organic Carbon (TOC) analysis. Given the background level of carbon in the control vessels and also the low level of carbon in the test vessels, it was considered that all the results were around the limit of quantification of the analytical method. The results of the test are considered to be reliable.

Executive summary:

Introduction

A study was performed to assess the acute toxicity of the test item to Daphnia magna. The method followed was designed to be compatible with the OECD Guidelines for Testing of Chemicals (April 2004) No 202, "Daphnia sp., Acute Immobilisation Test" referenced as Method C.2 of Commission Regulation (EC) No. 440/2008.

 

Methods…….

Due to the low aqueous solubility and complex nature of the test item, for the purposes of the test, the test medium was prepared as a Water Accommodated Fraction (WAF).

 

In the definitive test, twenty daphnids (4 replicates of 5 animals) were exposed to Water Accommodated Fractions (WAFs) of the test item at nominal loading rates of 10 and 100 mg/L for 48 hours at a temperature of approximately 21°C under static test conditions. The number of immobilized Daphnia and any adverse reactions to exposure were recorded after 24 and 48 hours.

 

Results…….

Samples of the control and the 10 and 100 mg/L loading rate WAFs were taken at 0 (fresh media) and 48 hours (old media) for Total Organic Carbon (TOC) analysis. Given the background level of carbon in the control vessels and also the low level of carbon in the test vessels, it was considered that all the results were around the limit of quantification of the analytical method.

 

Given that the toxicity cannot be attributed to a single component or a mixture of components, but to the test item as a whole, the results were based on nominal loading rates only.

 

Exposure of Daphnia magna to the test item gave EL₅₀values of greater than 100 mg/L loading rate WAF. The No Observed Effect Loading Rate was 100 mg/L loading rate WAF.

Description of key information

There is no data available for this substance. However, key data is available for structural analogues, Hyd C10-C12, isoalkanes, <2% arom; Hyd, C10-C13, ni, <2% aromatics. The data is read across to this substance based on analogue read across and a discussion and report on the read across strategy is provided as an attachment in IUCLID Section 13.

Hyd C10-C12, isoalkanes, <2% arom 48-hour LL50 is reported as >1000 mg/L. There was no mortality at the 1000 mg/L loading level after 48 hours. Therefore, the 48-hour LL0 for mortality is reported as 1000 mg/L. There was also no mortality in the control.

Hyd C10-C12, isoalkanes, <2% arom the 96-hour LL50 is reported as >1000 mg/L. There was no mortality at the 320 and 1000 mg/L loading levels after 96 hours. However, effects on swimming and feeding behavior were observed in the 320 and 1000 mg/L loading levels.

Hyd, C10-C13, ni, <2% aromatics EL50 values of greater than 100 mg/L Daphnia magna. The No Observed Effect Loading Rate was 100 mg/L loading rate WAF.

Additional information

Three study reports were available and input as endpoint records. The studies were scientifically reliable according to Klimish (Klimish et al., 1997) scoring (Klimish 1 and 2).

The water accommodated fraction (WAF) of Hyd C10-C12, isoalkanes, <2% arom did not produce a 50% effect (immobility) with Daphnia magna at a loading of 1000 mg/L after a 48-hour exposure. Therefore, the 48-hour LL50 is reported as >1000 mg/L. There was no mortality at the 1000 mg/L loading level after 48 hours. Therefore, the 48-hour LL0 for mortality is reported as 1000 mg/L. There was also no mortality in the control.

The water accommodated fractions (WAFs) of Hyd C10-C12, isoalkanes, <2% arom did not produce a 50% effect (mortality) with Chaetogammarus marinus after 96 hours at loadings up to 1000 mg/L. Therefore, the 96-hour LL50 is reported as >1000 mg/L. There was no mortality at the 320 and 1000 mg/L loading levels after 96 hours. However, effects on swimming and feeding behavior were observed in the 320 and 1000 mg/L loading levels.

The exposure of Daphnia magna to Hyd, C10-C13, ni, <2% aromatics gave EL50values of greater than 100 mg/L loading rate WAF. The No Observed Effect Loading Rate was 100 mg/L loading rate WAF.