1-imino-1H-isoindol-3-amine

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017-08-08 to 2017-08-10

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Sampling method: at test start and after 24 hours from fresh and aged solutions and after 48 hours from aged solutions.
- Sample storage conditions before analysis: all samples were analysed immediately after sampling

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION:
- Stock solution: 100 mg of test item was mixed with test medium and homogenised for 15 minutes of sonication; Final volume is 1000mL
- Dilutions of stock solution: 3 dilutions were made from the stock solution with test medium, to reach a final volume of 455mL per dilution
- Controls: test water without addition of the test item

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
- Use condition for main test: freshly hatched daphnids less than 24 hours old

Test type:

semi-static

Water media type:

freshwater

Remarks:

Elendt M4

Limit test:

no

Total exposure duration:

48 h

Hardness:

232 mg/L CaCO3

Test temperature:

Mean temperature: 19.7 ± 0.3 °C

pH:

Mean pH of untreated control: 7.93 ± 0.25

Dissolved oxygen:

Mean oxygen concentration: 9.0 ± 0.1 mg/L

Nominal and measured concentrations:

Nominal concentrations: 100, 45.5, 20.7, 9.39 and 4.27 mg/L and control
Measured concentrations (based on geometric means): 64, 28.2, 14.1, 6.39, 2.82 mg/L and n.d.

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 concentration (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 and behavioural changes

RANGE-FINDING STUDY
- Test concentrations: control, 100, 10 and 1 mg/L
- Sampling points : after 24h and 48h
- Results used to determine the conditions for the definitive study:
- after 24h 100% of the daphnids were found to be immobile at the highest test item concentration of 100 mg/L
- after 48h 5% of the daphnids were found immobile at 1.00 mg/L and 35 % at 10.0 mg/L. 100 % immobilisation was observed at the highest test item concentration of 100 mg/L.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate, two concentrations of this reference substance were tested around the same time period as the study

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

10.7 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

6.39 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Details on results:

- Observations in control group: after 24 and 48 hours of exposure no immobilisation was observed in the control and up to and including 9.39 mg/L (nominal)
More details in 'Any other information on results'

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Tets concencentrations: 1 and 2 mg/L (20 organisms per test concentration)
- Relevant effect levels: the results indicate an EC50 (24h) of the reference item above 1 mg/L. Results were in accordance with the requirements of the OECD guideline 202.

non-GLP range finding test

	Nominal test concentration (mg/L)
	Control	1	10	100
Group 1	0	1	3	5
Group 2	0	0	0	5
Group 3	0	0	1	5
Group 4	0	0	2	5
Sum	0	1	6	20
%	0	5	30	100

Summary of biological results main study:

a) Results of the test, 24h values:

	Control	4.27	9.39	20.7	45.5	100
	immobilised daphnids after 24 h
Group 1	0	0	0	0	3	5
Group 2	0	0	0	0	3	5
Group 3	0	0	0	1	3	5
Group 4	0	0	0	0	4	5
Σ	0	0	0	1	13	20
%	0	0	0	5	65	100

b) Results of the test, 48h values:

	Control	4.27	9.39	20.7	45.5	100
	immobilised daphnids after 48 h
Group 1	0	0	0	5	5	5
Group 2	0	0	0	5	5	5
Group 3	0	0	0	5	5	5
Group 4	0	0	0	4	5	5
Σ	0	0	0	19	20	20
%	0	0	0	95	100	100

Analytical results: determination of the test item in the test samples:

Test item	Sampling	Test item		Test item concentration measured [mg/L]
nominal [mg/L]	[h]	[mg/L]	% of nominal

Control	0 h		< LOD		-
	24 h fresh		< LOD		-		-
	48h aged		< LOD		-
4.27	0 h		3.43		80
	24 h fresh		3.71		87		2.82
	48h aged		2.21		52
9.39	0 h		7.02		75
	24 h fresh		8.52		91		6.39
	48h aged		5.27		56
20.7	0 h		16.2		78
	24 h fresh		19.6		95		14.1
	48h aged		11.2		54
45.5	0 h		36.5		80
	24 h fresh		38.5		85		28.2
	48h aged		20.9		46
100	0 h		82.7		83
	24 h fresh		89.5		90		64.0
	48h aged		46.7		47

Validity criteria fulfilled:

yes

Conclusions:

The 48-hour EC50 for Daphnia magna is of 10.7 mg/L (measured, geom. mean) and the NOEC is 6.39 mg/L (measured, geom. mean).

Executive summary:

The short-term toxicity to Daphnia magna was determined according to OECD 202 guidelines 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, 45.5, 20.7, 9.39 and 4.27 mg of the test item/L and a control. The measured concentrations (based on geometric means) are 64, 28.2, 14.1, 6.39, 2.82 mg/L and n.d., respectively.

Since the test concentration decreased with time, the geometric mean of the analysed concentrations was used to assess the effect levels. The EC50 value was determined to be 10.7 mg/L (measured, geom. mean) and the NOEC is 6.39 mg/L (measured, geom. mean).

Description of key information

A short-term toxicity to Daphnia magna is available for this test substance and was determined according to OECD 202 guidelines with no deviations. The study was conducted under semi-static conditions with 5 test concentrations plus control. Daphnids were exposed for 48h.

The EC50 value was determined to be 10.7 mg/L (measured, geom. mean). The NOEC was found to be 6.39 mg/L (measured, geom. mean)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

10.7 mg/L

Additional information

An OECD 202 study was conducted under semi-static conditions. The daphnids were exposed over a period of 48 hours to different nominal concentrations of 100, 45.5, 20.7, 9.39 and 4.27 mg of the test item/L and a control. The corresponding measured concentrations (based on geometric means) are 64, 28.2, 14.1, 6.39, 2.82 mg/L and n.d., respectively.

The EC50 value was determined to be 10.7 mg/L (measured, geom. mean). The NOEC was found to be 6.39 mg/L (measured, geom. mean)