Hydrocarbons, C10-C13, aromatics, >1% naphthalene

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:

1993

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:

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)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

Individual treatment solutions were prepared as Water Accommodated Fractions (WAFs). This included adding test substance to glass vessels, which contained dilution water and mixing for approximately 24 hours with a magnetic stirrer to produce a series of geometrically-spaced loading rates (mg/L). After mixing, the WAFs were allowed to settle for an hour. Each aqueous phase was then drawn off and transferred to two
150 mL Erlenmeyer flasks which were completely filled. Two further flasks were filled with dilution water only and served as controls.

Test organisms (species):

Daphnia magna

Details on test organisms:

Organisms were supplied by in-house cultures. The laboratory culture is derived from a clone held at ICI Brixham Laboratory. The ICI clone was itself obtained from the Institut de Recherche Chimique Applique (I.R.Ch.A.), France. Test organisms age = <24 hours old; parents age = 15 - 28 days.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

Water hardness of the control dilution water was 174 mg/L as CaCO3.

Test temperature:

Test temperature was 20 – 22 ºC.

pH:

The pH ranged from 7.7 to 8.1.

Dissolved oxygen:

Dissolved oxygen was 8.3 to 8.6 mg/L for "new" solutions and 8.6 to 8.7 mg/L for "old" solutions.

Salinity:

freshwater

Nominal and measured concentrations:

Nominal treatment levels were control, 0.1, 0.4, 1.0, 3.0 and 10 mg/L, which at t=0 measured non detected (< 2.5 mg/L), NA (not analyzed), NA, NA, 3.3 mg/L and 8.2 mg/L, respectively.

Details on test conditions:

Ten Daphnia magna, less than 24 h old, were added to each flask. The flasks were sealed with black caps that excluded air from the vessel. After 24 and 48 h the numbers of immobilized D.magna were recorded. D.magna were considered to be immobile, if, when the contents of the flask were swirled they did not swim during a 15 second period of observation.

Photoperiod with a 16 h : 8 h light : dark lighting regime.

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

>= 3 - <= 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

See Table in Remarks on Results

Reported statistics and error estimates:

Loading rates causing a 50% effect were determined by visual inspection of the data. They are expressed as being within a range bounded by loading rates that were tested. This is considered more appropriate for test materials that are mixtures of substances of different solubilities than is an interpolative statistical technique.

Nominal Loading	Measured Conc	Daphnia Immobilized
(mg/L)	(mg/L)	(@ 24, 48 hrs)*
Control	<LoD	0,0
0.1	<LoD	0, 0
0.4	<LoD	0, 0
1.0	<LoD	0, 0
3.0	3.3 – 3.1 **	0, 0
10.0	8.2 – 7.8 **	10, 10

*10 daphnids added to each of the control and treatment levels (both in duplicate) at test initiation

** Measured concentrations refer to the t=0h (fresh) and t=48 h (old) samples

Validity criteria fulfilled:

yes

Conclusions:

Water accommodated fractions of hydrocarbons, C10, aromatics, >1% naphthalene, produced a 48-hour LL50 value between 3 and 10 mg/L with Daphnia magna.

Executive summary:

Water accommodated fractions of hydrocarbons, C10, aromatics, >1% naphthalene, produced a 48-hour LL50 value between 3 and 10 mg/L with Daphnia magna.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16-Jan-1992 to 18-Jan-1992

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

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

Qualifier:

according to guideline

Guideline:

EPA OPP 72-2 (Aquatic Invertebrate Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Samples were removed from the fresh solutions at initiation and on Day 1. Samples were also removed from the old solutions on Day 1.

Vehicle:

no

Details on test solutions:

Individual treatment solutions were prepared as either a water accommodated fraction (WAF) or serial dilution of a stock WAF. A WAF was prepared for the two highest treatments (1.0 and 4.0 mg/L) by adding test substance to 1.0 L of medium in a 1 liter flask, mixing for 24 hours, and then removing the WAF from below the surface using a siphon. The lower treatment solutions were prepared by making serial dilutions of a WAF prepared as described above at a loading of 1.0 mg/L. Serial dilutions were prepared for the lower treatment solutions because of the difficulty in accurately preparing the renewal solutions at these lower treatment levels. Each test solution was renewed after 24 hours with a freshly prepared WAF solution. Dilution water was laboratory blend water with a hardness of 40 to 48 mg/L CaCO3.

Test organisms (species):

Daphnia magna

Details on test organisms:

Test organisms came from in-house cultures. Original source was Academy of Natural Sciences of Philadelphia, Division of Environmental Research, Philadelphia, PA, USA. Test organisms were <24 hours old from 16 day-old parents.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

None

Hardness:

40 to 48 mg/L as CaCO3.

Test temperature:

Test temperature was 19.6 Deg C.

pH:

The pH ranged from 7.8 to 8.0.

Dissolved oxygen:

Dissolved oxygen was 9.0 to 9.2 mg/L for "new" solutions and 8.3 to 9.1 mg/L for "old" solutions.

Salinity:

freshwater

Nominal and measured concentrations:

Nominal treatment levels were control, 0.01, 0.05, 0.1, 0.5, 1.0, and 4.0 mg/L, which measured non detected, NA (not analyzed), NA, 0.051, 0.228, 0.814, and 3.74 mg/L, respectively.

Details on test conditions:

Lighting was 67 to 76 ft candles with 16 hrs light and 8 hrs dark. Test vessels were 250 ml glass beakers in duplicate filled with 240 ml of solution. All test vessels were covered. Each replicate contained 10 organisms.

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

1.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CI = 0.95 - 1.8

Details on results:

48-hour EL50 = 1.1 mg/L (95% CI 0.95 to 1.8 mg/L) based upon nominal values 48-hour EC50 = 0.95 mg/L (95% CI 0.76 to 1.48 mg/L) based upon measured values.

Reported statistics and error estimates:

The 48-hr EC50 values were determined using the Probit Procedure of SAS.

Nominal Loading             Total
or Concentration      Daphnia Immobilized
(mg/L)                          (@ 24, 48 hrs)*

Control                            0, 0
0.01  (nominal)**           1, 1
0.05  (nominal)**           0, 0
0.05  (measured)           0, 0
0.23  (measured)           0, 1
0.81  (measured)           0, 7
3.74  (measured)          17, 20

*20 daphnids added to each of the control and treatment levels at test initiation.
**Test solutions were not analyzed or included in the statistical  analyses due to lack of significant mortality.

Validity criteria fulfilled:

yes

Conclusions:

Water accommodated fractions of hydrocarbons, C10-C13, aromatics, >1% naphthalene, produced a 48-hour EL50 value of 1.1 mg/l with the water flea (Daphnia magna).

Executive summary:

Water accommodated fractions of hydrocarbons, C10-C13, aromatics, >1% naphthalene, produced a 48-hour EL50 value of 1.1 mg/l with the water flea (Daphnia magna).

Description of key information

There is data available for this substance. Additionally, key and supporting data is available for the structural analogue Hydrocarbons, C10, aromatics, >1% naphthalene. The data for this substance is presented in the dossier. 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.

Hydrocarbons, C10, aromatics, >1% naphthalene, presented a 48-h EL50 (mobility) for Daphnia magna of between 3 and 10 mg/L (WAF) (Shell 1993b) and 10 mg/L (WAF) (Exxon 2006b).

Hydrocarbons, C10-C13, aromatics, >1% naphthalene, presented a 48-h EL50 (mobility) for Daphnia magna of 1.1 mg/L (WAF).

Additional information

Three study reports were available and input as endpoint records.

The study from Shell (1993b) examined the short-term toxicity of the test substance Hydrocarbons, C10, aromatics, >1% naphthalene, to Daphnia Magna. Groups of 10 daphnids (in duplicate) were exposed to nominal treatment levels of 0, 0.1, 0.4, 1.0, 3.0 or 10.0 mg/L of the test substance. Daphnids were exposed for 48h and after 24 and 48 h the numbers of immobilized Daphnia Magna were recorded. The 48h EL50 for Daphnia Magna was between 3 and 10 mg/L (WAF).

 

The study from Exxon (2006b) examined the short-term toxicity of the test substance Hydrocarbons, C10-C13, aromatics, >1% naphthalene, to Daphnia Magna. Five daphnids were added to each replicate and the replicates sealed. The test was performed under static conditions with no aeration. Daphnids were exposed to nominal treatment levels of 0, 0.45, 1.8, 4.3, 12.0 or 26.0 mg/L of the test substance. Daphnids were exposed for 48h and after 24 and 48 h the numbers of immobilized Daphnia Magna were recorded. The 48h EL50 for Daphnia Magna was 10 mg/L.

The study from Exxon (1992) examined the short-term toxicity of the test substance Hydrocarbons, C10, aromatics, >1% naphthalene, to Daphnia Magna. 20 daphnids were added to each of the control and treatment levels at test initiation. Nominal treatment levels were control, 0.01, 0.05, 0.1, 0.5, 1.0, and 4.0 mg/L. Each test solution was renewed after 24 hours with a freshly prepared WAF solution. Daphnids were exposed for 48h and after 24 and 48 h the numbers of immobilized Daphnia Magna were recorded. The 48h EL50 for Daphnia Magna was 1.1 mg/L (WAF).