2-Thiazolamine, 4-(2-naphthalenyl)-

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:

Study test phase 2012-08-20 to 2012-08-25. Study report completed 2012-10-26.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Report on substances meets the criteria for classification as reliable without restriction according to Klimisch et al (1997).

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

4-(naphthalen-2-yl)-1,3-thiazol-2-amine

EC Number:

606-740-6

Cas Number:

21331-43-1

Molecular formula:

C13H10N2S

IUPAC Name:

4-(naphthalen-2-yl)-1,3-thiazol-2-amine

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Nominal 0.0029, 0.0093, 0.030, 0.095, 0.31, 0.98, 3.1 and 10 mg/L
- Sampling method: Samples for analysis were taken at 0h from the excess test solutions and at 72h from a single test replicate of each exposure.

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A nominal 100 mg/L primary stock solution of the test substance was prepared by the addition of 0.10g of test substance to dilution water to a final volume of 1000ml. This stock solution was given 60 minutes ultrasonic treatment followed by approximately 24h stirring after which it was observed to be a cloudy solution. The stock solution was then centrifuged at 40000G for 20 minutes at 22 deg. C to separate the undissolved test substance. The supernatant was then carefully removed and used to prepare the nominal 10 mg/L test solution, by dilution of an appropriate aliquot. The remaining test solutions were prepared by the addition of aliquots of the 10 mg/L test solution to dilution water to final volumes of 1000ml.
- Controls: Culture medium only
- Chemical name of vehicle: Dilution water
- Evidence of undissolved material: The control and all test solutions were observed to be clear and colourless solutions.

Test organisms

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Strain: CCAP 278/4
- Source: laboratory culture at Brixham Environmental Laboratory
- Age of inoculum (at test initiation): 4 days

ACCLIMATION
- Culturing media and conditions: same as test

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

22 +/- 2 deg. C

pH:

6.42-7.43

Nominal and measured concentrations:

At the start of the test (0h) , the measured concentrations for the nominal concentrations 0.0029, 0.0093 and 0.030 mg/L were below the limit of quantification. The geometric mean measured concentrations for the nominal concentrations 0.095, 0.31, 0.98, 3.1 and 10 mg/L over the 72h test period ranged from 3 to 5% of the nominal values. At 72h the measured concentrations for the nominal concentrations 0.0029, 0.0093 and 0.030 mg/L were below the limit of quantification.

The geometric mean measured test substance concentrations were used for the calculation and reporting of the results.

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass conical flasks
- Type: closed with foam bungs
- Material, size, headspace, fill volume: flasks of 250ml nominal capacity containing 100ml of test solution.
- Aeration: none
- Type of flow-through: none
- Initial cells density: 5320 cells/ml
- Control end cells density: 514000 cells/ml
- No. of vessels per concentration (replicates):3
- No. of vessels per control (replicates):6

GROWTH MEDIUM
- medium used:AAP-medium(OECD 201)

OTHER TEST CONDITIONS
- Sterile test conditions: no
- Adjustment of pH: not required
- Photoperiod: Continuous illumination
- Light intensity and quality: approx. 6000 lux

EFFECT PARAMETERS MEASURED
- Observation intervals: 24, 48 & 72h
- Determination of cell concentrations: electronic particle counter

TEST CONCENTRATIONS
- Test concentrations: nominal concentrations of 0.0029, 0.0093, 0.030, 0.095, 0.13, 0.98, 3.1 and 10 mg/L

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.39 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks:

(cell particle density)

Remarks on result:

other: 0.33-0.42 mg/L 95% CL

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.083 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks:

(cell particle density)

Remarks on result:

other: 0.060-0.13 mg/L 95% CL

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

0.13 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks:

(cell particle density)

Remarks on result:

other: 0.095-0.21 mg/L 95% CL

Effect concentrations 4

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.035 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks:

(cell particle density)

Effect concentrations 5

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

0.13 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks:

(cell particle density)

Effect concentrations 6

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 0.48 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 7

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.25 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 0.17-0.30 mg/L 95% CL

Effect concentrations 8

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

0.48 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 9

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.035 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 10

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

0.13 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

- Exponential growth in the control: yes
- Observation of abnormalities: cells appeared normal for the control and test concentrations at the end of the test.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In this algal study the 72h EC50 based on yield at the end of the test was 0.39 mg/L (used mean measured concentration). The 72h EC50 based on the growth rate was >0.48 mg/L (using mean measured concentration). Therefore, the test substance demonstrated some toxic effect on the algae in this study.

Executive summary:

Introduction

This study was undertaken to determine the toxicity of the test substance to the green alga Pseudokirchneriella subcapitata. The procedure employed was in accordance with the guideline:

OECD Test Guideline 201, Freshwater Alga and Cyanobacteria, Growth Inhibition Test. Adopted 23 March 2006.

Results and Conclusions

In this algal study the 72h EC50 based on yield at the end of the test was 0.39 mg/L (used mean measured concentration). The 72h EC50 based on the growth rate was >0.48 mg/L (using mean measured concentration). Therefore, the test substance demonstrated some toxic effect on the algae in this study.