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

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:

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.

Justification for type of information:

The justification for read across is provided as an attachment in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across: supporting information

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

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).

This data is read across to Hydrocarbons, C11-C15, aromatics, <1% naphthalene.