Hydrocarbons, C6-C7, n-alkanes, isoalkanes, cyclics, <5% n-hexane

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:

25 January - 2 August 1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Justification for type of information:

A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

yes (incl. QA statement)

Remarks:

The Department of Health of the Government of the United Kingdom

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Water accomodated fractions (WAFs) were prepared. The test substance was added to test medium and stirred for 43 hrs. Vessels had minimal headspace to prevent volitilization. Contents of the vessels were then allowed to settle for 1-2 hrs. Aqueous phase was used for the test. Controls were subject to the same regime

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Source: clone held at Zeneca Brixham Laboratory; the clone itself was obtained from the Institut National de Recherche Chimique Applique (I.R.Ch.A.), France
- Age at study initiation (mean and range, SD): < 24 h
- Method of breeding: for the first 14 days Daphnia are cultured in 1L beakers containing 0.8L of reconstituted freshwater. From Day 15 onwards they are cultured in a 2L beaker containing 1.5 L of reconstituted freshwater. New cultures are started with animals less than 24 h old, at a density of about 10 per vessel. Cultures are held at nominally 18-22°C, under artificial light in a 16 h light 8 h dark cycle.


ACCLIMATION
- Acclimation conditions (same as test or not): yes
- Type and amount of food: concentrated suspensions of Chlorella vulgaris to give a concentration of approx. 0.10 x 10^6 cells/mL
- Feeding frequency: daily

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

186 mg/L as CaCO3

Test temperature:

18.0 - 18.6°C

pH:

7.9 - 8.3

Dissolved oxygen:

9.1 - 9.2 mg/L

Nominal and measured concentrations:

0, 1, 2.2, 4.6, 10, 22 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type: closed
- Material, size, headspace, fill volume: 150 mL Erlenmeyer flasks with no headspace
- Renewal rate of test solution (frequency/flow rate): no renewal
- 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: reconstituted fresh water prepared by dissolving different Analar grade salts in reverse osmosis as recommended by the U.S. EPA (1975).
- Total organic carbon: 2.5 mg/L
- Chlorine: 0.02 mg/L Cl2
- Alkalinity: 257 mg/L CaCO3
- Ca/mg ratio: 48:1
- Conductivity: 496 µs/cm
- Culture medium different from test medium: no
- Intervals of water quality measurement: 6 months


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

TEST CONCENTRATIONS
- Range finding study
- Results used to determine the conditions for the definitive study: 48h EL50: 1-10 mg/L

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

EL50

Effect conc.:

>= 10 - <= 22 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EL0

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

>= 4.6 - <= 10 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EL0

Effect conc.:

4.6 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

mobility

Reported statistics and error estimates:

Loading rates used to produce WAF that cause a 50% effect (LL50) were estimated by visual inspection of the data. This was considered more appropriate than an interpolative statistical analysis when considering toxicity data based on WAF of test substances that are mixtures containing components of low solubility.

 Table: Immobilisation of D. magna exposed to water accomodated fractions of SBP 100/140

Loading rate used to produce WAF (mg/L)	Number of D. magna	Number immobilised
		24h	48h
Control	10	0	0
	10	0	0
1	10	0	0
	10	0	0
2.2	10	0	0
	10	0	0
4.6	10	0	0
	10	0	1
10	10	0	10
	10	2	10
22	10	10	10
	10	10	10

Validity criteria fulfilled:

yes

Conclusions:

This study examined the short-term toxicity of hydrocarbons, C7-C9, n-alkanes, isoalkanes, cyclics to Daphnia. Groups of 10 Daphnia were exposed to loading rates of 0, 1, 2.2, 4.6, 10, or 22 mg/L. Daphnia were exposed for 48-hrs with no test solution renewal. Daphnia were observed at 24 and 48hrs after start. No analytical monitoring was done as studies of closely related products has shown that the solubility of the test substance is likely to be less than the determination limit of the analytical equipment. All Daphnia exposed to 22 mg/L of test substance were immobilised. At a concentration of 10 mg/L all Daphnia exposed for 48hrs were immobilise and two at 24 hrs. Only 1 Daphnia was immobilised at a concentration of 4.6 mg/L at 48 hrs. The 48-hr EL50 for Daphnia is 4.6-10 mg/L WAF.

Executive summary:

This study examined the short-term toxicity of hydrocarbons, C7-C9, n-alkanes, isoalkanes, cyclics to Daphnia. Groups of 10 Daphnia were exposed to loading rates of 0, 1, 2.2, 4.6, 10, or 22 mg/L. Daphnia were exposed for 48-hrs with no test solution renewal. Daphnia were observed at 24 and 48hrs after start. No analytical monitoring was done as studies of closely related products has shown that the solubility of the test substance is likely to be less than the determination limit of the analytical equipment. All Daphnia exposed to 22 mg/L of test substance were immobilised. At a concentration of 10 mg/L all Daphnia exposed for 48hrs were immobilise and two at 24 hrs. Only 1 Daphnia was immobilised at a concentration of 4.6 mg/L at 48 hrs. The 48-hr EL50 for Daphnia is 4.6 -10 mg/L WAF.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17 March 1993 - 19 December 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

yes (incl. QA statement)

Remarks:

The Department of Health of the Government of the United Kingdom

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The following salts were added to Millipore or reverse-osmosis filtered water: 192 mg/L NaHCO3, 120 mg/L CaSO4.2H2O, 240 mg/L MgSO4.7H2O, 8 mg/L KCl. 100 g/L soil extract in reconstituted water is autoclaved for 15 min. at 120 degree C and added at 20 ml/L. Solids are vacuumed filtered. This test medium is mixed with test substance for 24 hrs, then allowed to settle for 1 hr. Aqeous phase was then used in the experiment.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Source: laboratory culture, obtained from Institut National de Reschereche Chimique Applique (I.R.Ch.A.), France
- Age at study initiation (mean and range, SD): less than 24 hrs old
- 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.

ACCLIMATION
- Acclimation period: Young are left for at least one hour prior to the study to select for actively swimming individuals.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

178 mg/L CaCO3

Test temperature:

17-18°C

pH:

7.1-8.2

Dissolved oxygen:

9.0-9.5 mg/L

Nominal and measured concentrations:

0, 0.89, 2, 4.5, 10, 22 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type: sealed with black caps
- Material, size, headspace, fill volume: 150 mL Erlenmeyer flasks, completely filled, no headspace
- Aeration: none
- Renewal rate of test solution (frequency/flow rate): no renewal
- 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: laboratory mains supply, filtered (10 µm) and passed through activated carbon
- Alkalinity: 253 mg/L
- Conductivity: 510 µs/cm

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Immobilization was determined at 24 and 48 hrs after start of exposure.

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

EL50

Effect conc.:

12 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

mobility

Remarks on result:

other: 95% CL: 9.8-16

Key result

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

3 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

mobility

Remarks on result:

other: 95% CL: 2.5-3.7

Duration:

24 h

Dose descriptor:

EL0

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EL0

Effect conc.:

2 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

mobility

Details on results:

- Mortality of control: There was no mortality of control.

Reported statistics and error estimates:

Statistics: moving average angle technique or probit analysis

Table: Immobilisation of D. magna exposed to water accomodated fractions of SBP 60/95 LNH:

Loading rate to produce WAFs (mg/L)	Number of D. magna	Number immobilised
		24h	48h
Control	10	0	0
	10	0	0
0.89	10	0	0
	10	0	1
2	10	0	0
	10	0	0
4.5	10	0	10
	10	0	8
10	10	0	10
	10	0	10
22	10	10	10
	10	10	10

Validity criteria fulfilled:

yes

Conclusions:

This study examined the short-term toxicity of the test substance, hydrocarbons, C6-C7, n-alkanes, isoalkanes, cyclics, < 5% hexane, to Daphnia magna. Groups of 10 daphnids were exposed to loading rates of 0, 0.89, 2, 4.5, 10, or 22 mg/L test substance. Daphnids were exposed for 48 hrs, and there was no renewal of test solution. Daphnids were observed at 24 and 48 hrs after start of exposure for immobilization. The 48-hr EL50 for Daphnia magna was 3.0 mg/L (WAF).

Executive summary:

This study examined the short-term toxicity of the test substance, hydrocarbons, C6 -C7, n-alkanes, isoalkanes, cyclics, < 5% hexane, to Daphnia magna. Groups of 10 daphnids were exposed to loading rates of 0, 0.89, 2, 4.5, 10, or 22 mg/L test substance. Daphnids were exposed for 48 hrs, and there was no renewal of test solution. Daphnids were observed at 24 and 48 hrs after start of exposure for immobilization. The 48-hr EL50 for Daphnia magna was 3.0 mg/L (WAF).

Description of key information

There is data available for this substance. Additionally, key and supporting data is available for structural analogue Hydrocarbons C7-C9, n-alkanes, isoalkanes, cyclics. 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. Key information is summarised below:

The test substance hydrocarbons, C7-C9, n-alkanes, isoalkanes, cyclics exhibited a 48-hr EL50 for 4.6-10 mg/L WAF for Daphnia magna.

 

The test substance, hydrocarbons, C6 -C7, n-alkanes, isoalkanes, cyclics, < 5% hexane, exhibited 48-hr EL50 of 3.0 mg/L (WAF) for Daphnia magna.

 

Additional information

Three key study reports were available and input as endpoint records. These studies are summarised below.

The study from Shell (1995) examined the short-term toxicity of hydrocarbons, C7-C9, n-alkanes, isoalkanes, cyclics to Daphnia. Groups of 10 Daphnia were exposed to loading rates of 0, 1, 2.2, 4.6, 10, or 22 mg/L. Daphnia were exposed for 48-hrs with no test solution renewal. Daphnia were observed at 24 and 48hrs after start. No analytical monitoring was done as studies of closely related products has shown that the solubility of the test substance is likely to be less than the determination limit of the analytical equipment. All Daphnia exposed to 22 mg/L of test substance were immobilised. At a concentration of 10 mg/L all Daphnia exposed for 48hrs were immobilise and two at 24 hrs. Only 1 Daphnia was immobilised at a concentration of 4.6 mg/L at 48 hrs. The 48-hr EL50 reported for Daphnia magna is 4.6 -10 mg/L WAF.

 

The study from Shell (1994a) examined the short-term toxicity of the test substance, hydrocarbons, C6 -C7, n-alkanes, isoalkanes, cyclics, < 5% hexane, to Daphnia magna. Groups of 10 daphnids were exposed to loading rates of 0, 0.89, 2, 4.5, 10, or 22 mg/L test substance. Daphnids were exposed for 48 hrs, and there was no renewal of test solution. Daphnids were observed at 24 and 48 hrs after start of exposure for immobilization. The 48-hr EL50 reported for Daphnia magna was 3.0 mg/L (WAF).