4-(hydroxymethyl)-4-methyl-1-phenylpyrazolidin-3-one

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:

30 October 2017 to 23 November 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: Guidance document on aquatic toxicity testing of difficult substances and mixtures, OECD series on testing and assessment number 23, 2000.

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

4-(hydroxymethyl)-4-methyl-1-phenylpyrazolidin-3-one

EC Number:

235-920-3

EC Name:

4-(hydroxymethyl)-4-methyl-1-phenylpyrazolidin-3-one

Cas Number:

13047-13-7

Molecular formula:

C11H14N2O2

IUPAC Name:

4-(hydroxymethyl)-4-methyl-1-phenylpyrazolidin-3-one

Test material form:

solid: particulate/powder

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: all concentrations at 0 and 24 h (fresh) and at 24 and 48 h (old) --> 2.0 mL from the approximate centre of the test vessels
- Sample storage conditions before analysis: anaylsed freshly
- sample preparation:diluted in a 1:1 (v:v) ratio with 1% L-ascorbic acid in ISO-medium and analyzed ( the substance is known to be stable in 0.5% L-ascorbic acid in water)

Test solutions

Vehicle:

no

Details on test solutions:

Preparation of test solutions started with the highest concentration of 100 mg/L with 21 minutes of magnetic stirring to accelerate dissolution of the test item in medium. Lower test concentrations were prepared by subsequent dilutions of the highest concentration in test medium. At the end of the preparation procedure, all test solutions were clear and differed in color from very light yellow/brown to yellow/brown with increasing test concentration.
Due to the light sensitive nature of the test item, preparation was performed under dimmed light and the glassware was wrapped in aluminum foil.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain/clone: Straus, 1820
- Source: in-house laboratory culture
- Age of parental stock (mean and range, SD): < 24 H
- Feeding during test: none

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

180 mg/L as CaCO3

Test temperature:

20 - 21°C

pH:

7.7-8.1

Dissolved oxygen:

7.3-10 mg/L

Salinity:

NA

Nominal and measured concentrations:

Nominal: 2.2, 4.6, 10, 22, 46 and 100 mg/L
measured (TWA) : 0.85, 1.7, 3.8, 8.4, 20 and 44 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 60 mL glass with 50 mL test solution
- Aeration: No
- Renewall of test solution: at 24 h:
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS: according to the guideline (adjusted ISO medium)

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: in dark

EFFECT PARAMETERS MEASURED: immobility at 24 and 48 hours

RANGE-FINDING STUDY
- Test concentrations: 0, 0.10, 1.0 and 10 mg/L
- Results used to determine the conditions for the definitive study: immobility at 48 h 0, 10, 60 and 100% at 0, 0.10, 1.0 and 10 mg/L

Reference substance (positive control):

yes

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

4 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Results with reference substance (positive control):

EC50 of potassium dichromate 0.41 mg/L with a 95% confidence interval between 0.34 and 0.46 mg/L

Reported statistics and error estimates:

95% confidence interval substance EC50 3.2 – 5.1 mg/L
Probit analysis with ToxRat Professional v 3.2.1 (ToxRat Solutions® GmbH, Germany)

Any other information on results incl. tables

Immobility

Time (h)	Replicate	CH01610; Average exposure concentration (mg/L)
		Control	0.85	1.7	3.8	8.4	20	44
0	A	5	5	5	5	5	5	5
	B	5	5	5	5	5	5	5
	C	5	5	5	5	5	5	5
	D	5	5	5	5	5	5	5
	Total introduced	20	20	20	20	20	20	20
24	A	0	0	0	1	2	2	5
	B	0	0	0	1	3	4	5
	C	0	0	0	1	3	4	5
	D	0	0	0	0	3	4	5
	Total immobilised	0	0	0	3	11	14	20
	Effect %	0	0	0	15	55	70	100
48	A	0	0	1	4	4	5	n.d.
	B	0	0	0	2	5	5	n.d.
	C	0	0	0	2	4	5	n.d.
	D	0	0	0	4	3	5	n.d.
	Total immobilised	0	0	1	12	16	20	n.a.
	Effect %	0	0	5	60	80	100	n.a.

 

sample analyses

CH01610 Nominal concentration (mg/L)	Measured concentrations (mg/L)				Average exposure (mg/L)
	t=0h (fresh)	t=24h (old)	t=24h (fresh)	t=48h (old)
2.2	1.8	0.39	1.7	0.42	0.85
4.6	3.5	0.67	3.7	0.85	1.7
10	8.2	1.5	8.5	2.1	3.8
22	18	3.5	18	4.4	8.4
46	38	8.6	39	11	20
100	83	23	n.d.	n.d.	44^1

n.d. – not determined,¹ calculated based only on the results obtained in the first renewal, i.e. as mathematical means of the concentrations of the substance measured in the samples taken at the start (C_t=0), after 24 hours in old (C_{t=24, old}) and fresh medium (C_{t=24, fresh}) and at the end of the test (C_t=48).

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 48 h EC50 of the substance for daphnia magna was 4 mg/L (based on measured concentrations)

Executive summary:

In a test according to OECD 202 with a semi-static designe (renewal after 24 h), daphnids were exposed to the test substance at 2.2, 4.6, 10, 22, 46 and 100 mg/L (nominal) for 48 hours. Analyses of the fresh and old solutions showed that concentrations dropped to 18 -29% of initial. The time weight average concentrations were 0.85, 1.7, 3.8, 8.4, 20  and 44 mg/L. Immobilisation was observed at 3.8 mg/L and above. The EC50 was 4.0 mg/L.