Registration Dossier

Ecotoxicological information

Long-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

Endpoint:
long-term toxicity to aquatic invertebrates
Type of information:
(Q)SAR
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Well documented publication
Justification for type of information:
QSAR prediction
Principles of method if other than guideline:
Alcohol ethoxylte specific QSAR, with the log Kow as the predictor variable. The structure activity relationship was evaluated based on data of standardized 21-day reproduction tests, with Daphnia magna.
GLP compliance:
no
Test organisms (species):
Daphnia magna
Water media type:
freshwater
Limit test:
no
Total exposure duration:
21 d
Duration:
21 d
Dose descriptor:
other: EC20
Effect conc.:
0.088 mg/L
Nominal / measured:
estimated
Conc. based on:
test mat.
Basis for effect:
reproduction
Endpoint:
long-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable, well documented publication which meets basic scientific principles
Justification for type of information:
Please refer to the Category Approach Justification provided in Section 13
Qualifier:
according to
Guideline:
other: USEPA-TSCA (U.S. EPA, 1992)
Qualifier:
according to
Guideline:
other: ASTM (1988) guidelines
GLP compliance:
no
Analytical monitoring:
yes
Vehicle:
no
Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: waterflea
- Justification for species other than prescribed by test guideline: no
- Source: stock culture maintained at the University of Mississippi Ecotoxicology Laboratory
- Age of parental stock (mean and range, SD): less than 24 h
- Feeding during test
- Food type: Selenastrum sp. and Ankistrodesmus sp.
- Amount: 5 mL of concentrated algae of above stated species per daphnid
- Frequency: twice daily (in the morning and in the late afternoon)


ACCLIMATION
- Acclimation conditions (same as test or not): daphnids were allowed to acclimate to test temperature prior to introduction into exposure chambers.
Test type:
flow-through
Water media type:
freshwater
Limit test:
no
Total exposure duration:
21 d
Hardness:
mean: 77.5 mg/L as CaCO3 (range: 74.0 mg/L - 80.0 mg/L as CaCO3)
Dilution water with an average hardness of approximately 8 mg/L as CaCO3 was adjusted to 80 mg/L as CaCO3 by addition of calcium chloride and sodium bicarbonate.
Test temperature:
mean: 20.5 °C (range: 19.0 - 22.3 °C)
pH:
mean: 8.1 (range: 7.8 - 8.2)
Dissolved oxygen:
mean: 8.6 mg/L (range: 6.2 - 9.4 mg/L)
Nominal and measured concentrations:
nominal: 0.5, 1.0, 2.0, 3.0 and 6.0 mg/L
mean measured: 0.39, 0.77, 1.75, 2.69 and 5.21 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: 250 mL borosilicate glass beakers with screened overflow outlets (100 µm mesh) that maintained solution volume at approximately 200 mL.
- Aeration: dilution water was aerated
- Type of flow-through (e.g. peristaltic or proportional diluter): FMI fluid-piston metering pumps (FMI Inc., New York, NY, USA)
- Renewal rate of test solution (frequency/flow rate): flow rates of each chamber were maintained at 2 mL/min by control valves, resulting in approximately 14 volume additions per chamber daily.
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: spring water collected daily from the University of Mississippi Biological Field Station.
- Alkalinity: mean: 72.4 mg/L as CaCO3 (range: 70.0 - 75.0 mg/L as CaCO3)
- Conductivity: mean: 325 µ/cm (range: 312 - 349 µ/cm)
- Intervals of water quality measurement: 3 - 5 days during exposure


OTHER TEST CONDITIONS
- Photoperiod: 16 h light : 8 h darkness
Reference substance (positive control):
no
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
0.77 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
reproduction
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
1.75 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
immobilisation
Details on results:
- Mortality of parent animals: 97% survival of the control organisms
- No. of offspring produced per day per female: control: see table below

Measured concentration
[mg/L]

# Young

0

6.75

0.39

6.46

0.77

6.16

1.75

1.131

2.69

0.112

5.21

02

1significantly different from control

2not included in reproduction NOEC calculation due to significant survival

effects (significantly different from control)

Endpoint:
long-term toxicity to aquatic invertebrates
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Justification for type of information:
Please refer to the Category Approach Justification provided in Section 13
Reason / purpose:
read-across source
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
0.77 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
reproduction
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
1.75 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
immobilisation

Description of key information

EC20 (21d) = 0.088 mg/L for Daphnia magna reproduction (QSAR estimation)

Key value for chemical safety assessment

Additional information

As there are no data available for alcohol ethoxylate C16, <2.5EO (CAS 9004-95-9), a read-across is prepared to a chronic invertebrate study conducted with a similar alcohol ethoxylate (C12-13, 6.5 EO). This 21 days flow-through chronic experiment on Daphnia magna is conducted according to the guidelines USEPA-TSCA (U.S. EPA, 1992) and ASTM (1988) and is well documented in the publication by Gillespie et al. (1999). The reported NOEC for reproduction is 0.77 mg/L.

Nevertheless, data do not allow to derive a precise long-term effect value for the described alcohol ethoxylate C16, <2.5EO (CAS 9004-95-9). Alcohol ethoxylate specific QSARs were developed to describe the toxicity of varying mixtures (Wind & Belanger, 2006; Boeije et al., 2006; Belanger et al, 2006). The QSARs considered all three trophic levels (algae, invertebrates and fish). The effects are described as EC20 values, since the QSARs are more robust for the EC20 values than for NOEC or EC10 values (Boeije et al., 2006). For the described alcohol ethoxylate C16, <2.5EO (CAS 9004-95-9), the QSAR for long-term toxicity on reproduction of Daphnia magna (Boeije et al., 2006) results in an EC20 (21d, reproduction) of 0.088 mg/L. This result is used as key value for classification and labeling.