3-hydroxy-2'-methoxy-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:

2017/09/04-2017/12/11

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:

3-hydroxy-2'-methoxy-2-naphthanilide

EC Number:

205-206-6

EC Name:

3-hydroxy-2'-methoxy-2-naphthanilide

Cas Number:

135-62-6

Molecular formula:

C18H14NNaO3

IUPAC Name:

3-hydroxy-2'-methoxy-2-naphthanilide

Test material form:

solid

Details on test material:

- Batch number: 1366154001
- Purity: 98.7%
- Appearance / colour: solid/ yellow-brown
- Expiry date: 31 May 2019

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Sampling method: analytical samples taken at 0 hours and 24 hours from fresh and after 24 and 48 hours from aged test solutions were analysed from control and the test item loading rates of 31.3 and 100 mg/L. Analyses were made only on concentrations were effects were seen, concentrations below were only monitored, not reported.
- Fortified samples: stock solutions of the test item (2450 mg/L, purity not considered) were prepared in acetonitrile. Dilutions (100 mg/L) and (1 mg/L) were prepared in acetonitrile/water (1:1, v/v). The stock solution and the 1 mg/L dilution were used for fortification of 0.006 mg/L and 40 mg/L recovery samples.
- Sample storage (before test): stored deep-frozen (≤ - 18 °C) 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:

semi-static

Water media type:

other: Elendt M4

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

232 mg/L CaCO3

Test temperature:

mean temperature of the control and all test item loading rates: 20.4 ± 0.7 °C

pH:

mean pH-value of the untreated control: 7.95 ± 0.05

Dissolved oxygen:

mean oxygen concentration: 9.0 ± 0.2 mg/L

Nominal and measured concentrations:

Nominal concentrations: 100, 31.3, 9.77, 3.05, 0.954 mg/L and control
Test item loading rates (geometric mean measured): 3 mg/L (corresponding to 100), 1.25 mg/L (corresponding to 31.3), other values were only monitored (not reported) and for the control it was not determined

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 test item loading rates (4 replicates of 5 animals each)
- No. of treatment groups: 6 (5 dose rates 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
- Photoperiod: 16/8 hours light/dark cycle

EFFECT PARAMETERS MEASURED: Immobilisation

RANGE-FINDING STUDY
- Test concentrations: control, 100, 10 and 1 mg/L
- Sampling points : after 24h and 48h of exposure
- Results used to determine the conditions for the definitive study:
- after 24 h 0% of the daphnids were found to be immobile in the control and up to and including 10 mg/L, 60% immobilisation was observed at 100 mg/L
- after 48 h 0 % of the daphnids were found to be immobile in the control, 10% were found immobile at 1 mg/L and 10 mg/L, 75% were found immobile at 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.:

2.31 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.:

1.25 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Details on results:

- Observations in control group: no immobilisation observed during test period

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 between 1 and 2 mg/L

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	0.954	3.05	9.77	31.3	100
	immobilised daphnids after 24 h
Group 1	0	0	0	0	0	2
Group 2	0	0	0	0	0	4
Group 3	0	0	0	0	0	4
Group 4	0	0	0	0	0	1
Σ	0	0	0	0	0	11
%	0	0	0	0	0	55

b) Results of the test, 48h values

	nominal test item loading rate [mg/L]
	Control	0.954	3.05	9.77	31.3	100
	immobilised daphnids after 24 h
Group 1	0	0	0	0	0	2
Group 2	0	0	0	0	0	4
Group 3	0	0	0	0	0	4
Group 4	0	0	0	0	0	1
Σ	0	0	0	0	0	11
%	0	0	0	0	0	55

Determined concentration of test substance:

Test item loading rate		Sampling		Test substance				Geometric mean concentration		Test item concentration
nominal [mg/L]		[h]		[mg/L]		% of nominal		[%]		measured[mg/L]
Control	0 fresh		n.d.		-				-
	24 aged		n.d.		-
	24 fresh		n.d.		-
	48 aged		n.d.		-
31.3	0 fresh		2.72		9		4		1.25
	24 aged		0.550		2
	24 fresh		2.69		9
	48 aged		0.569		2
100	0 fresh		11.8		12		3		3.00
	24 aged		1.59		2
	24 fresh		5.69		6
	48 aged		1.108		1

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 48-hour EC50 for Daphnia magna is 2.31 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 semi-static conditions. The daphnids were exposed over a period of 48 hours to different nominal concentrations of 100, 31.3, 9.77, 3.05, 0.954 mg/L and a control. The measured concentrations are 3 mg/L (corresponding to 100) and 1.25 mg/L (corresponding to 31.3), the other values were only monitored (not reported) and for the control it was not determined.

The validity criteria were fulfilled.

The EC50 value was determined to be 2.31 mg/L (measured, geom. mean).