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

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Test phase 2012-08-20 to 2012-08-24. Study report 2012-10-26.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Report on substance 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 202 (Daphnia sp. Acute Immobilisation 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 (mg/L): Control, 5.3, 9.5, 17, 31, 56 & 100 of test substance.
- Sampling method: Excess test solutions were sampled at the start of the test. At the end of the test one replicate of the control and each test concentration were sampled.

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A primary stock solution of 100 mg/L of test substance was prepared by adding 200mg of test substance to 2000mL of water. This was ultrasonicated for 1 hour and stirred overnight. To remove undissolved particles of test substance the stock concentrate was centrifuged at 40000G for 20 min. at 20 deg. C. The supernatant was carefully removed from below the surface to ensure minimum disturbance of the solution. The supernatant was clear and colourless with fine white particles. The resultant solution was used directly as the highest test concentration and appropriate aliquots were diluted to prepare the remaining test solutions.
- Controls: Dilution water only
- Chemical name of vehicle: Dilution water (Elendt's M4 Daphnia magna medium)

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia
- Source: Continuous laboratory culture held by testing lab, Brixham Environmental Laboratory.
- Age at study initiation (mean and range, SD): <24h
- Method of breeding: diploid parthenogenesis
- Feeding during test: none

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

Dilution water 236 mg/L (as CaCO3)

Test temperature:

Test concentrations 20.5-20.6 deg. C

pH:

Test concentrations 8.07-8.19

Dissolved oxygen:

Test concentrations 7.84-8.19 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beakers
- Type: Covered with loose fitting glass lids
- Material, size, headspace, fill volume: 100ml nominal capacity beakers containing 80ml of test solution providing a depth of approx. 50mm.
- Aeration: none
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Preparation of dilution water: Elendt and Bias M4 Daphnia magna medium(Elendt and Bias (1990) Trace Nutrient Deficiency in Daphnia magna Cultured in Standard Medium for Toxicity Testing. Effects of the Optimisation of Culture Conditions on Life History Parameters of D.magna. Water Research, 24, 1157-1167).
- Total organic carbon: <1 mg/L
- Particulate matter:<3mg/L suspended solids at 105 deg. C
- Pesticides: Highest organochlorine pesticides <0.01 ug/L, Highest organophosphorous pesticide <0.01 ug/L
- Alkalinity: 36.8 mg/L as CaCO3
- Conductivity: 593 uS/cm at 25 deg. C
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Photoperiod: 16h light and 8h dark, with 20 min. dawn/dusk transition.

EFFECT PARAMETERS MEASURED: An assessment of the response of the D.magna at 24 and 48h. Each Daphnia was oberved by eye and was considered affected if showing no whole body movement within a 15 sec. period, even if movement of individual appendages was visible. Affected D.magna were termed immobile. Any overt symptoms of toxicity were also recorded.

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

4.7 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 3.0-7.4 mg/L 95% CL

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

2.2 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 2.1-2.3 mg/L 95% CL

Effect concentrations 3

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

1.4 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 4

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

1.9 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

After 24h the daphnia in the 12 mg/L test vessels, which were not immobilised, were observed to be very slow moving. The presence of the very slow moving Daphnia were noted as an overt symptom of toxicity.

At the start of the test the measured concentration of test substance ranged from 0.75 to 7.96 mg/L. After 48h exposure the measured concentratons ranged from 0.67 to 18 mg/L. The geometric mean measured concentration over the test period ranged from 7 to 15% of nominal values.

The mean measured concentration of the test substance in the nominal 100 mg/L after 48h exposure was determined to be 18 mg/L. The 48h measured concentration is above the concentration recorded at the start of the test. A white deposit was observed on the bottom of the nominal 31, 56 and 100 mg/L test vessels, after 48h exposure, this deposit is assumed to be test substance. Accidental carry over of some of the deposited material is believed to be the cause of the elevated measured concentration in the 48h 100mg/L sample as all the other test concentrations showed a decline in test substance concentration over the exposure period.

A geometrioc mean measured concentration was used for the calculation and reporting of results.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In this Daphnia study the 48h EC50 of the test material was calculated to be 2.2 mg/L (based on geometric mean measured concentration). The 24h EC50 of the test material was calculated to be 4.7 mg/L. The 48h NOEC was determined to be 1.4 mg/L and the LOEC was determined to be 1.9 mg/L. Therefore, in this study the test substance demonstrated some toxicity to Daphnia magna.

Executive summary:

Introduction

This study was undertaken to assess the acute toxicity of the test substance to Daphnia magna. The study was in accordance with guideline:

OECD Test Guideline 202, D.magna sp., Acute Immobilisation Test. Adopted 13 April 2004.

Results and Conclusions

In this Daphnia study the 48h EC50 of the test material was calculated to be 2.2 mg/L (based on geometric mean measured concentration). The 24h EC50 of the test material was calculated to be 4.7 mg/L. The 48h NOEC was determined to be 1.4 mg/L and the LOEC was determined to be 1.9 mg/L. Therefore, in this study the test substance demonstrated some toxicity to Daphnia magna.