2,4-dihydro-4-[4-[4-(4-methoxyphenyl)piperazin-1-yl]phenyl]-3H-1,2,4-triazol-3-one

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017-01-06 to 2017-01-20

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: Guidance document on aquatic toxicity testing of difficult items and mixtures, OECD series on testing and assessment number 23, December 14, 2000

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

2,4-dihydro-4-[4-[4-(4-methoxyphenyl)piperazin-1-yl]phenyl]-3H-1,2,4-triazol-3-one

EC Number:

278-009-6

EC Name:

2,4-dihydro-4-[4-[4-(4-methoxyphenyl)piperazin-1-yl]phenyl]-3H-1,2,4-triazol-3-one

Cas Number:

74853-07-9

Molecular formula:

C19H21N5O2

IUPAC Name:

4-{4-[4-(4-METHOXYPHENYL)PIPERAZIN-1-YL]PHENYL}-2,4-DIHYDRO-3H-1,2,4-TRIAZOL-3-ONE

Test material form:

solid: particulate/powder

Details on test material:

- Name of test material (as cited in study reports): JNJ-1802905-AAA (T001328)
- Physical state: solid
- Appearance: Purple powder

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: I16AB0441
- Expiration date of the lot/batch: 2018-01-30 (retest date)
- Purity test date: 2016-02-18 (certificate of analysis relase date)

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: at room temperature
- Stability under test conditions: not indicated
- Solubility and stability of the test substance in the solvent/vehicle: < 0.001 g/L

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Sampling method: samples were taken before the start of the test, after 24 hours and after 72 hours from each test medium and from the control. 3.0 mL of volume was taken. At the end of the exposure period, the replicates with algae were pooled at each concentration before sampling.
- Sample storage conditions before analysis: stored in a freezer until analysis. Additionally, reserve samples of 3.0 mL were taken for possible analysis

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Due to an expected low water solubility of the test item, a saturated solution (SS) was prepared. The preparation of test solutions started with a loading rate of 100 mg/L applying a three-day period of magnetic stirring at room temperature to ensure maximum dissolution of the test item in test medium. This resulted in a hazy dispersion containing undissolved material. The obtained dispersion was filtered through a 0.45 µm membrane filter (Whatman; RC55). The filter was pre-conditioned with a small volume of test solution that was discarded. The resulting SS was used as the highest test concentration. Lower test concentrations were prepared by subsequent dilutions of the SS in test medium. After preparation, volumes of 50 mL were added to each replicate of the respective test concentration. Subsequently, 1 mL of an algal suspension was added to each replicate providing a cell density of 10^4 cells/mL.
- Evidence of undissolved material (e.g. precipitate, surface film, etc): final test solutions were clear and colourless.

Test organisms

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Strain: NIVA CHL 1
- Source (laboratory, culture collection): In-house laboratory culture
- Method of cultivation: Algae stock cultures were started by inoculating growth medium (M1) with algal cells from a pure culture on agar. The suspensions were continuously aerated and exposed to light in a climate room at a temperature of 21-24°C.
- Pre-culture: 3 days before the start of the test, cells from the algal stock culture were inoculated in culture medium (M2, according to OECD 201) at a cell density of 1 x 10^4 cells/mL. The pre-culture was maintained under the same conditions as used in the test. The cell density was measured immediately before use.

ACCLIMATION
- Acclimation period: not relevant (except pre-culture before start of the test)

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test conditions

Hardness:

24 mg CaCO3/L

Test temperature:

22-23°C

pH:

t=0h: 7.9
t=72h: 8.1

Dissolved oxygen:

not reported

Salinity:

not relevant

Conductivity:

not applicable

Nominal and measured concentrations:

Nominal concentrations (mg/L): 1.0, 10 and 100% of a SS prepared at 100 mg/L
Measured concentrations (mg/L):
at the start of the test: n.d, nm, nm, 0.0923 mg/L
after 24h: n.d., nm, nm, 0.0931 mg/L
after 72h: 0.000089, nm, nm, 0.0904 mg/L

n.d= not detected
nm = not measured

The measured concentration remained stable throughout the test duration, i.e. it was at the level of 98% of initial at the end of the test. Based on these results, the effect parameters were expressed in terms of the measured initial concentration.

Details on test conditions:

TEST SYSTEM
- Test vessel: beaker
- Material, size, headspace, fill volume: 100 ml, all-glass, containing 50 mL of test solution
- Initial cell density: 1 x 10^4 cells/ml
- No. of vessels per concentration and per control (replicates):
6 replicates of the control and the limit concentration;
3 replicates of each lower concentration;
1 extra replicate of each test concentration and the control for sampling purposes at 24h;
1 or 2 replicates of each test concentration without algae.

GROWTH MEDIUM
- Standard medium used: M1; according to the NPR 6505 (“Nederlandse Praktijk Richtlijn no. 6505”) formulated using Milli-RO water (tap-water purified by reverse osmosis
- Detailed composition if non-standard medium was used:
NaNO3 500 mg/L
K2HPO4.3H2O 52 mg/L
MgSO4.7H2O 75 mg/L
Na2CO3.10H2O 54 mg/L
C6H8O7.H2O 6 mg/L
NH4NO3 330 mg/L
CaCl2.2H2O 35 mg/L
C6H5FeO7.xH2O 6 mg/L
H3BO3 2.9 mg/L
MnCl2.4H2O 1.81 mg/L
ZnCl2 0.11 mg/L
CuSO4.5H2O 0.08 mg/L
(NH4)6Mo7O24.4H2O 0.018 mg/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: M2; according to the OECD 201 Guideline, formulated using Milli-RO water
- Culture medium different from test medium: Yes. Three days before the start of the test the algal stock culture were inoculated in the same culture medium (M2) used in the test. The culture was maintained under the same conditions as used in the test.
- Intervals of measurements: pH was measured at the beginning and at the end of the test (control and 100% filtrate). Temperature was continuously measured in a control vessel. At the end of the final test microscopic observations were performed on all test concentrations to observe for any abnormal appearance of the algae.

OTHER TEST CONDITIONS
- Sterile test conditions: no information.
- Adjustment of pH: no
- Photoperiod: continuous illumination
- Light intensity and quality: using TLD-lamps with a light intensity within the range of 84 to 86 µE/m²/s.


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : growth inhibition
- Determination of cell concentrations: At the beginning, cells were counted using a microscope and a counting chamber. thereafter, cell densities were determined by spectrophotometric measurement of samples at 680 nm using a spectrophotometer with immersion probe (pathlength = 20mm).
- effect calculated parameters: specific growth rate and yield

TEST CONCENTRATIONS
- Spacing factor for test concentrations: x10
- Range finding study: combined limit/range finding study was performed
- Test concentrations: 1.0, 10 and 100% of a SS prepared at 100 mg/L
- Results used to determine the conditions for the definitive study: no definitive study necessary

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 0.092 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.092 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

- Exponential growth in the control (for algal test): yes
- Any stimulation of growth found in any treatment: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no
- 72-h EC50 (yield) > 0.092 mg / L
- 72-h EC10 (growth rate) > 0.092 mg / L
- 72-h EC10 (yield) < 0.092 mg / L
- 72-h NOEC (yield) < 0.092 mg / L

Results with reference substance (positive control):

- Results with reference substance valid? yes
- EC50: 72h-ErC50 was 1.3 mg/L (95% confidence interval ranging from 1.2 to 1.4 mg/L)
- Other: the historical ranges for growth rate inhibition lie between 0.82 and 2.6 mg/L. The observed 72h-ErC50 for the algal culture tested corresponds with this range

Reported statistics and error estimates:

For determination of the NOEC and the EC50 the approaches recommended in the OECD guideline 201 were used. An effect was considered to be significant if statistical analysis of the data obtained for the highest test concentration compared with those obtained in the negative control revealed significant inhibition of growth rate or inhibition of yield (Two-sample t-test Procedure, á=0.05, onesided, smaller). No EC50-values could be calculated because the test item proved to be non-toxic (EC50 > maximum concentration tested).
The calculations were performed with ToxRat Professional v. 3.2.1. (ToxRat Solutions® GmbH, Germany).

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

A 72-h growth inhibition test with the unicellular algal species Pseudokirchneriella subcapitata was performed with the test substance JNJ-1802905-AAA (T001328) according to the OECD guideline 201 (GLP conditions). No biologically significant inhibition of growth rate of Pseudokirchneriella subcapitata was recorded at any of the concentrations tested. The EC50 for growth rate inhibition (72h-ERC50) and the EC50 for yield inhibition (72h-EYC50) were beyond the range tested, i.e. exceeded an initially measured concentration of 0.092 mg/L. The 72h-NOEC for growth rate inhibition was determined to be 0.092 mg/L. The 72h-NOEC for yield inhibition could not be determined. The results of the test can be considered reliable without restrictions.