5-oxo-DL-proline

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 October 2012 to 30 October 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results. The study report was conclusive, done to a valid guideline and the study was conducted under GLP conditions.

Reason / purpose for cross-reference:

other: Read-across target

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1075 (Freshwater and Saltwater Fish Acute Toxicity Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: JMAFF in Japan (12-Nousan-No.8147, 2-7-1-1, 24 November, 2000)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: The 100 mg/L and untreated control were sampled for analysis in the definitive test, all concentrations were determined in the preliminary tests.
- Sampling method: Test solution concentrations were determined at the beginning and end of the first and the last renewal periods (at 0, 24, 72 and 96 hours).

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Prior to treatment, a test solution of 100 mg/L was prepared by diluting an appropriate amount of test material in aquarium water. Because the 96 hours stability data of the test material was not available, the test was performed under semi-static conditions, therefore prior to each renewal period the test material solutions was freshly prepared.
- Controls: The dilution water (circulated and filtered) was used without of addition of the test item.

Test organisms (species):

Cyprinus carpio

Details on test organisms:

TEST ORGANISM
- Common name: Carp
- Length at study initiation: 4.1 – 7.1 cm.
- Weight at study initiation: The calculated mean weight of one fish at study initiation was 0.98 g and 1.24 g, in the control and exposure group respectively.
- Feeding during test: The fish were not fed during the test.

ACCLIMATION
- Acclimation period: > 12 days.
- Acclimation conditions: Same as test.
- Health during acclimation: Fish were bred in a well-known fish farm, under disease- and parasite-controlled conditions. Fish were observed during the acclimatisation and test periods, the fish were healthy. There was no mortality of the population for seven days before the test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

The hardness of the dilution water was determined to be 203 mg/L (as CaCO3).

Test temperature:

21.1 - 21.9 °C

pH:

8.20 – 8.36

Dissolved oxygen:

88 – 96 % of the air saturation value at the temperature used.

Nominal and measured concentrations:

100 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel: An aquarium.
- Fill volume: 20 L
- Renewal rate of test solution: 24 hours
- No. of organisms per vessel: Seven per concentration.
- No. of vessels per concentration: One replicate.
- No. of vessels per control: One replicate.
- Biomass loading rate: 1.0 g fish/L test solution at the start of the experiment

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Aquarium water, not specified.
- Intervals of water quality measurement: The test conditions (pH, temperature, oxygen saturation) were examined at each renewal period during the test.

OTHER TEST CONDITIONS
- Photoperiod: The light-dark cycle during the test was 16 hours light and 8 hours darkness.

EFFECT PARAMETERS MEASURED
Mortality and any sub-lethal effect were determined at 3, 6, 24, 48, 72 and 96 hours.
The body weights of the fish were recorded before study initiation.

TEST CONCENTRATIONS
- Range finding study: Two preliminary concentration range-finding tests were conducted to determine the approximate toxicity of the test material so that appropriate test concentrations could be selected for use in the definitive test. In the first preliminary study five fish were exposed to each concentration of the test material plus a control, for 96 hours under static conditions, while four fish were exposed to each concentration of the test material plus a control, for 96 hours under semi-static conditions during the second preliminary test.
During the formulation of the second pre-test procedure the test solutions were prepared by similar method described for the definitive test.
- Test concentrations:
> First preliminary test: Untreated control (0.0), 0.1, 1, 10 and 100 mg/L
> Second preliminary test: Untreated control (0.0), 1, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: Since a significant toxic response was not observed during the preliminary range-finding tests, one test concentration (100 mg/L) and one control group were chosen to be tested in a limit test for the definitive study.
The test concentration was analytically determined at the start and at the end of the first and the last renewal periods (at 0, 24, 72 and 96 hours).
The corresponding measured geometric mean test item concentration was 99.07 mg/L.
As the measured concentration deviated not more that 20 per cent from the nominal in all cases, biological results are based on the nominal concentration.
> First preliminary test:
Nominal Concentration (mg/L) 0.0 0.1 1 10 100
No. of Treated Fish 5 5 5 5 5
No. of Dead Fish 0 0 0 0 0

> Second preliminary test:
Nominal Concentration (mg/L) 0.0 1 10 100
No. of Treated Fish 4 4 4 4
No. of Dead Fish 0 0 0 0

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Mortalities: No mortalities occurred during the observation period in either the control or treated groups, see Table 2.
- Signs of Toxicity: No signs of toxicity were observed in either group.

Reported statistics and error estimates:

No statistical analysis was performed because of the lack of toxic effects.
The LC50, NOEC, and LOEC were determined directly from the raw data.

Sublethal observations / clinical signs:

Analysis of Test Solution Concentrations

The corresponding measured geometric mean test material concentration was 99.07 mg/L. As the measured concentration deviated not more than 20 per cent from the nominal in all cases, biological results are based on the nominal concentration. See Table 1 for HPLC results.

Table 1: Results of Test Solution Analysis

Nominal Concentration (mg/L)	Measured Concentration on the First Day of the Test				Measured Concentration on the Last Day of the Test
	mg/L		% of the Nominal		mg/L		% of the Nominal
	Start	End	Start	End	Start	End	Start	End
Control (0.0)	Not Detected		-		-		-
100	103.5 ± 2.04	91.4 ± 3.03	104	91	108.2 ± 2.58	94.1 ± 3.61	108	94

Table 2: Cumulative Mortality Data

Nominal Test Concentration (mg/L)	Mortality Rate of Treated Fish (Dead Fish/Treated Fish)
	3 hours	6 hours	24 hours	48 hours	72 hours	96 hours
Control (0.0)	0/7	0/7	0/7	0/7	0/7	0/7
100	0/7	0/7	0/7	0/7	0/7	0/7

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the test, no mortality or systemic signs of toxicity were observed during the exposure period. Therefore the NOEC was determined to be 100 mg/L, the LOEC > 100 mg/L. and the LC50 was determined to be > 100 mg/L.

Executive summary:

The toxicity of the test material to fish was determined in an acute toxicity study performed under GLP conditions and in line with the standardised guidelines OCED 203, EU Method C.1 and EPA OPPTS 850.1075.

During the study Cyprinus carpio were exposed to the test material at a nominal concentration of 100 mg/L in a semi-static limit test, with an exposure period of 96 hours. Renewal was performed ever 24 hours throughout the exposure period. An untreated control was run concurrently for comparison. The concentration used in the definitive test was based on the results of two preliminary tests, in which no mortality was observed up to a maximum concentration of 100 mg/L. Analytical verification of the test solution concentration gave a geometric mean concentration of 99.07 mg/L, since the measured concentration deviated less than 20 % from the nominal biological results are based on the nominal concentration.

Under the conditions of the study no mortality or systemic signs of toxicity were observed in any of the treated fish. Based on these observations the NOEC was determined to be 100 mg/L, the LOEC > 100 mg/L, and the LC50 > 100 mg/L.

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study conducted on read-across material.

Justification for type of information:

Read-across from a structurally similar substance. Please refer to the RAAF report (section 13) for further information/ justification.

Reason / purpose for cross-reference:

read-across source

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Description of key information

Under the conditions of the study on the read-across substance no mortality or systemic signs of toxicity were observed in any of the treated fish. Based on these observations the NOEC was determined to be 100 mg/L, the LOEC > 100 mg/L, and the LC50 > 100 mg/L.

Additional information

The toxicity of the read-across material to fish was determined in an acute toxicity study performed under GLP conditions and in line with the standardised guidelines OCED 203, EU Method C.1 and EPA OPPTS 850.1075. The study was awarded a reliability score of 1 in accordance with the criteria set forth by Klimisch et al. (1997).

During the study Cyprinus carpio were exposed to the test material at a nominal concentration of 100 mg/L in a semi-static limit test, with an exposure period of 96 hours. Renewal was performed ever 24 hours throughout the exposure period. An untreated control was run concurrently for comparison. The concentration used in the definitive test was based on the results of two preliminary tests, in which no mortality was observed up to a maximum concentration of 100 mg/L. Analytical verification of the test solution concentration gave a geometric mean concentration of 99.07 mg/L, since the measured concentration deviated less than 20 % from the nominal biological results are based on the nominal concentration.

Under the conditions of the study no mortality or systemic signs of toxicity were observed in any of the treated fish. Based on these observations the NOEC was determined to be 100 mg/L, the LOEC > 100 mg/L, and the LC50 > 100 mg/L.