5'-chloro-3-hydroxy-2',4'-dimethoxy-2-naphthanilide

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:

2016/07/26-2017/12/11

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

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

5'-chloro-3-hydroxy-2',4'-dimethoxy-2-naphthanilide

EC Number:

202-182-9

EC Name:

5'-chloro-3-hydroxy-2',4'-dimethoxy-2-naphthanilide

Cas Number:

92-72-8

Molecular formula:

C19H16ClNO4

IUPAC Name:

5'-chloro-3-hydroxy-2',4'-dimethoxy-2-naphthanilide

Test material form:

solid

Details on test material:

- Batch: 16021485
- Purity: 95.9%
- Colour: solid/greyish
- Expiry date: 2017-10-21
- Storage conditions: ambient (5-30 °C), dark, dry

Specific details on test material used for the study:

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
-The test item has a low water solubility, therefore, the test item was applied as water accommodated fraction (WAF).
The WAF was used as application solution (~ 50 mL of the prepared solution was transferred to each test vessel).

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Sampling method: analytical samples taken at 0 hours (initial value) and 48 hours from aged test solutions were analysed from control and test item loading rate. Analyses on sampling point 24h were made but not reported on the Result Tables.
- Fortified samples: a stock solution (2000 mg/L, purity not considered) was prepared in acetonitrile. A dilution (10 mg/L) was prepared in acetonitrile. The stock solution and the 10 mg/L dilution was used for fortification of 0.03 mg/L and 60 mg/L recovery samples.
- Sample storage (before test): stored deep-frozen until analysis

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain/clone: straus, clone 5
- Feeding during test: no feeding during test
- Feeding of culture (before test): three times a week with single cell green algae
- Main test: freshly hatched daphnids less than 24 hours old were used

Study design

Test type:

static

Water media type:

other: Elendt M4

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Hardness:

232 mg/L CaCO3

Test temperature:

20.0 – 21.8 °C

pH:

7.61 – 7.91

Dissolved oxygen:

≥ 8.4 mg/L

Nominal and measured concentrations:

Nominal concentration: 100 mg/L and a control
Measured concentration (geometric mean based): 4.31 mg/L and not determined for the control

Details on test conditions:

TEST SYSTEM
- Test vessel: glass vessel
- Type: covered with a glass plate (to reduce evaporation)
- Material, size, headspace, fill volume: 100 mL capacity filled with 50mL of test solution
- No. of organisms: 20 daphnids per treatment group (4 replicates of 5 animals each)
- No. of treatment groups: 2 (1 dose rate of the test item and a control)

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt M4
- Culture medium different from test medium: same as Elendt M4

OTHER TEST CONDITIONS
- Exposure to light: none

EFFECT PARAMETERS MEASURED: Immobilisation

RANGE-FINDING STUDY
- Test concentrations: control, 100, 10, 1 and 0.1 mg/L
- Sampling points : after 24h and 48h of exposure
- Results used to determine the conditions for the definitive study:
-After 24 hours of exposure no immobilisation above the allowed control immobilisation was observed in the control and up to and including 100 mg/L.
-After 48 hours of exposure no immobilisation was observed in the control and up to and including 10.0 mg/L. 15 % immobilisation was observed at the highest test item loading rate of 100 mg/L.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate, tested at 1.00 and 2.00 mg/L with 20 test organisms per test concentration, at around the same time period as the study

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 4.31 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 4.31 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Test concencentrations: 1 and 2 mg/L (20 organisms per test concentration)
- Relevant effect levels: EC50 (24h) is below 1 mg/L. The results are in accordance with the requirements of the OECD guideline 202.

Any other information on results incl. tables

Summary of biological results:

a) Results of the test, 24h values

	Nominal test item loading rate [mg/L]
	Control	100
	immobilised daphnids after 24 h
Group 1	0		0
Group 2	0		0
Group 3	0		0
Group 4	0		0
Σ	0		0
%	0		0

b) Results of the test, 48h values

	Nominal item loading rate [mg/L]
	Control	100
	immobilised daphnids after 48 h
Group 1	0		0
Group 2	0		0
Group 3	0		0
Group 4	0		0
Σ	0		0
%	0		0

Determined concentration of test substance:

Test item loading rate		Test item	Sampling	Test item found		Test item concentration
nominal [mg/L]		Nominal  [mg a.i./L]	[h]	[mg/L]	% of nominal	actual [mg/L]
Control	0		0 fresh	n.d.	-	-
			24 aged	n.d.	-
			48 aged	n.d.	-
100	100		0 fresh	33.2	33	4.31
			24 aged	0.668	0.668
			48 aged	0.456	0.456

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 48-hour EC50 for Daphnia magna is > 4.31 mg/L (measured, geom. mean).

Executive summary:

The short-term toxicity to Daphnia magna was determined according to OECD 202 guideline with no deviations. The study was conducted under static conditions, and it was a limit test. The daphnids were exposed over a period of 48 hours to a nominal concentration of 100 mg/L and a control. The measured concentration is 4.31 mg/L and for the control it was not determined.

The validity criteria were fulfilled.

The EC50 value was determined to be > 4.31 mg/L (measured, geom. mean).