Registration Dossier

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
26 to 28 February 2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Justification for type of information:
The acute toxicity to Daphnia study was undertaken as a bridging study to demonstrate equivalence between the Target substance (XP 475) and the Source substance (XP 338; CAS 569318-35-0) for the read-across of other data. A full discussion of read-across and supporting data is given in the attached justification in the short-term toxicity to fish.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Version / remarks:
April 13, 2004
Deviations:
yes
Remarks:
Deviation: The control solution will be prepared in a similar manner with dilution water only. Reason: The control solution was not prepared in a similar manner to the WAF solution. Effect on study: None.
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
The concentration of XP 475 was determined by measuring the concentration of total aluminum in all control and test substance treatment solutions at 0 and 48 hours. The 0-hour samples were collected from the parent solutions and the 48-hour samples were collected after combining replicate test solutions by treatment.

Test solutions

Vehicle:
no
Details on test solutions:
Nominal Loading Rate Concentrations: 0 (control), 6.3, 13, 25, 50, and 100 mg total product (TP)/L.
The dilution water was a natural surface water collected on-site at the testing facility. The dilution water has a typical hardness of approximately 240 mg CaCO3/L and a pH of approximately 8.5.

A definitive test was performed at target nominal loading rate concentrations of 0 (control), 6.3, 13, 25, 50, and 100 mg total product (TP)/L. A primary standard solution was prepared as water accommodated fraction (WAF) by weighing 0.3002 g of XP 475 onto a glass cover slip, which was then dropped into a glass aspirator bottle containing 3.0 L of dilution water. The primary standard solution was clear and colorless with undissolved test substance on the bottom of the bottle. The solution was stirred using a Teflon®-coated magnetic stir bar with the vortex no greater than approximately 25% of the solution depth. The solution was covered to shield from light and stirred for approximately 72 hours at room temperature. Following termination of stirring, the solution was allowed to settle for approximately 24 hours. The solution was then passed through glass wool and a glass funnel and collected. The collected solution was passed through a 0.2 µm filter. Appropriate aliquots of the primary standard solution were diluted in 1.0 L of dilution water to prepare the 6.3, 13, 25, and 50 mg TP/L test treatment solutions. The primary standard solution was used as the 100 mg TP/L test treatment solution. The control solution consisted of dilution water only.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
Daphnia magna neonates (<24-hours old) were obtained from an in house daphnid culture. All daphnids were cultured in a temperature-controlled area at approximately 20°C. During the culture period, the daphnids were fed a suspension of the algal species Raphidocelis subcapitata (formerly Selenastrum capricornutum) at least once a day supplemented by an artificial diet consisting of a wheat grass, salmon starter, and yeast suspension (YCT). Less than 24 hours old neonates for the definitive test were collected from in-house culture containing adults that were approximately 23 days old. The adults were considered acceptable with no signs of stress, disease or physical damage. Since the culturing and testing environmental parameters were equivalent (i.e., temperature, dilution water, and lighting), no acclimation period was necessary. Test daphnids were not fed during the test.

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
48 h

Test conditions

Hardness:
180 mg CaCO3/L
Test temperature:
20.5 to 20.8°C
pH:
8.4 to 8.7
Dissolved oxygen:
4.9 to 8.7 mg/L (58 to 102% saturation)
Conductivity:
692 µS/cm
Nominal and measured concentrations:
Calculated concentrations of XP 475, based on total aluminum concentration, in the test substance treatment solutions at initiation were 0.14, 0.47, 1.1, 2.4, and 5.2 mg total product (TP)/L in the 6.3, 13, 25, 50, and 100 mg TP/L treatments, respectively, which represented recoveries of 2.2 to 5.2% of the nominal loading rate concentrations. Calculated concentrations of XP 475 in test solutions at 48 hours (termination) were reporting limit (0.010 mg total aluminum/L), 0.39, 1.0, 2.3, and 5.1 mg TP/L, which represented recoveries of 0.4 to 3.0% of the nominal loading rate concentrations. The overall mean calculated concentrations in the test substance treatment solutions during the 48-hour exposure were 0.073, 0.43, 1.1, 2.4, and 5.2 mg TP/L, which represented recoveries of 1.2 to 5.2% of the nominal loading rate concentrations. No residues of XP 475, based on total aluminum concentration, were detected in the control solutions above the reporting limit of 0.010 mg total aluminum/L.
Details on test conditions:
The test chambers utilized during the definitive test were 250 mL glass jars containing approximately 200 mL of control or test substance treatment solution and were covered with a clear lid. The test chambers were maintained at a range of 20 ± 1°C in a temperature-controlled water bath. Fluorescent lighting was maintained on a 16-hour daylight photoperiod with 30 minute simulated dawn and dusk periods. The measured light intensity at initiation of the definitive test was 664 lux as measured with a LI COR Model LI 250A light meter equipped with a photometric sensor.
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat. (dissolved fraction)
Basis for effect:
mobility
Key result
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat. (dissolved fraction)
Basis for effect:
mobility

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The 24- and 48-hour EC50 values were estimated to be >100 mg TP/L, the highest concentration tested. No sublethal effects were noted during the definitive test. The 48 hour NOEC was 100 mg TP/L.