Propanamide, N-[4-(2,4-dihydroxyphenyl)-2-thiazolyl]-2-methyl-

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:

04 Mar - 06 Mar 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Report date:

2014

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Landesamt für Umwelt, Wasserwirtschaft und Gewerbeaufsicht, Mainz, Germany

Test material

Test material information

Constituent 1

Reference substance name:

N-[4-(2,4-dihydroxyphenyl)-1,3-thiazol-2-yl]-2-methylpropanamide

EC Number:

807-621-3

Cas Number:

1428450-95-6

Molecular formula:

C13H14N2O3S

IUPAC Name:

N-[4-(2,4-dihydroxyphenyl)-1,3-thiazol-2-yl]-2-methylpropanamide

Test material form:

solid: particulate/powder

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Control, 10, 18, 32, 56 and 100 mg/L
- Sample storage conditions before analysis: The samples were analysed directly.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A saturated solution was prepared for the test. This was done by mixing the load of 100 mg with 1 L of dilution water and shaking vigorously for 24 h. The resulting solution was filtrated through 0.45 µm PTFE filters. The lower treatments were prepared by dilution of this saturated stock solution.
- Eluate: no
- Differential loading: no
- Controls: yes, test medium control

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain: Berlin
- Source: Umweltbundesamt, Berlin, Germany
- Age at study initiation (mean and range, SD): < 24 h
- Method of breeding: In-house breeding since 27 Sep. 2007. The husbandry is performed similar to the method described in EN ISO 6341, following SOP 115 002 01 („Zucht und Hälterung von Daphnia magna STRAUS“), edition 11, adopted 15 Jan 2013. Animals were bred in preserving glasses (2 L volume) in M4 medium. They were fed with Desmodesmus subspicatus and the medium is renewed twice a week. The photo-period is 16 h light / 8 h dark at a temperature of 20 ± 2 °C.
- Feeding during test: none

ACCLIMATION
- Acclimation period: 24 h before the start of the test, the adult animals were separated from the young. 23 h later, the adults were caught with the help of a glass tube, and the newborn Daphnia, aged between 0 and 23 h, were sieved from the medium and immediately placed into a 250 mL-beaker containing dilution water. After a settling-in period of 30 min, animals which showed no apparent damage were used for the test.
- Acclimation conditions (same as test or not): same as test

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Test temperature:

18.7 – 19.7 °C

pH:

7.7 - 7.8

Dissolved oxygen:

8.2 - 8.5 mg O2/L

Nominal and measured concentrations:

nominal: control, 10, 18, 32, 56, 100 mg/L
measured: < LOQ, 3.64, 6.36, 11.50, 20.10, 35.73 mg/L (geometric mean)

Details on test conditions:

TEST SYSTEM
- Test vessel: beakers
- Material, size, headspace, fill volume: glass, 50 mL, headspace: 30 mL, fill volume: 20 mL
- Aeration: no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Deionised water with an enrichment of certain minerals (as demanded in the guidelines) is used in the test.
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: The pH of the dilution water was adjusted to pH 7.8 ± 0.2.
- Photoperiod: 16 h light / 8 h dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Immobilisation was recorded after 24 and 48 h.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.7

Range finding study
- Test concentrations: 10 and 100 mg/L (non-GLP study)
- Results used to determine the conditions for the definitive study: 0% immobilisation was observed at 10 mg/L; 100% immbobilisation was observed in 100 mg/L.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

6.4 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

16 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: No behavioural abnormalities were observed in the control.
- Mortality of control: 0%

Results with reference substance (positive control):

- Results with reference substance valid? yes
- EC50/LC50: EC50 (48 h) 1.4 mg/L after 48 h
- Other: The EC50 lies within the demanded range of 0.6 – 1.7 mg/L.

Any other information on results incl. tables

Table 1: Immobilised daphnia after 24 and 48 h.

Nominal concentration [mg/L]	Geometric mean of measured concentration [mg/L]	Immobilised daphnia after 24 h					Immobilised daphnia after 48 h
		1	2	3	4	Sum %	1	2	3	4	Sum %
0	0	0	0	0	0	0	0	0	0	0	0
10	3.64	0	0	0	0	0	0	0	0	0	0
18	6.36	0	0	0	0	0	0	0	0	0	0
32	11.5	0	1	1	1	15	2	3	2	2	45
56	20.1	3	3	1	2	45	3	3	2	2	50
100	35.73	5	5	5	5	100	5	5	5	5	100

Table 2: Measured test concentrations

Nominal concentration [mg/L]	Measured concentration at t = 0 h [mg/L]	Measured concentration at t = 48 h [mg/L]	Geometric mean of measured concentration [mg/L]
0	< LOQ	< LOQ	--
10	3.53	3.75	3.64
18	6.13	6.61	6.36
32	11.00	12.02	11.50
56	19.19	21.05	20.10
100	34.01	37.53	35.73

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

A 48 h EC50i of 16 mg/L and a 48 h NOEC of 6.4 mg/L was determined.

Executive summary:

Two experiments were performed.

During the first experiment significant immobilization in the blank control was observed and

mistakenly, the test solution had been filtered using Nylon filters instead of PTFE filters.

Therefore, a second experiment was performed. The results of the first experiment are not

reported in detail in this report but all data will be archived under GLP-conditions.

The second experiment was performed using five concentrations ranging from

10 to 100 mg/L nominal concentration. Twenty Daphnia per concentration were exposed to

the test item for 48 hours in a static test system. After 24 and 48 hours, the immobilized

Daphnia were counted.

The three highest concentrations showed toxicity in the range of 45 - 100% immobilization

after 48 hours. None of the animals were immobilized in the control.

At the beginning and at the end of the test, the content of the test item in the test solutions

was determined using HPLC-determination. The measured concentrations were in the

range of 34 – 38% of the nominal concentration. This was caused by the limited solubility

of the test item in the test medium. Therefore, the determination of the biological results

was based on the geometric mean of the measured concentrations.

Potassium dichromate K2Cr2O7 (CAS No. 7778-50-9) was used as positive control in a

current reference study (14021101R201). The EC50 (48 h) value was determined as 1.4

mg/L, lying within the demanded range of 0.6 – 1.7 mg/L.

The following results were determined for the test item N-[4-(2,4-dihydroxyphenyl)thiazol-

2-yl]isobutyramide (species: Daphnia magna).

24 h-NOEC = 6.4 mg/L

48 h-NOEC = 6.4 mg/L

24 h-EC50i = 20 mg/L

48 h-EC50i = 16 mg/L