(7R)-7-(4-carboxybutanamido)cephalosporanate amidohydrolase (enzyme substance)

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 13-MAY-2002 to 05-AUG-2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The test was performed according to OECD guidelines and GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: all concentrations and the blank-control
- Sampling method: 10 ml was taken from the approximate centre of the test vessel
- Sample storage conditions before analysis: not applicable, samples were analysed on the day of sampling

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION: the test substance was dissolved in the test medium.
the test solutions were prepared using stock solutions of 1250 mg/l (range-finding test) or 2250 mg/l (final test). 10 to 15 minutes of magnetic stirring, and in the range-finding test and the final test at t=0 h also 5 minutes of ultra sonication, was necessary for the dissolving of the test substance in the test medium. The lower test concentrations were prepared by subsequent dilutions of the stock solution in test medium.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain: Daphnia magna (Crustacea, Cladocera)
- Source: internal breeding
- Age at study initiation: For the test selection of young daphnia with an age of < 24 hours
- Method of breeding: with new-born animals, i.e. less than 3 days old, by placing about 250 of them into 10 litres of medium in an all-glass culture vessel
- Feeding during test: no feeding during the test

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

none

Hardness:

data not available

Test temperature:

The temperature of the test medium measured in the blank control varied from 19.5 to 20.2 °C.

pH:

between 7.0 and 8.3 in all test concentrations

Dissolved oxygen:

from 0.96 to 9.0 mg/L

Salinity:

not applicable (freshwater)

Nominal and measured concentrations:

nomical concentrations:
- Aldolase: 0, 125, 225, 400, 700, 1250, 2250 mg/L
- protein: 0, 10, 18, 32, 56, 100, 180

measured concentrations: see table 1

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (open/closed): data not available
- Material, size, headspace, fill volume: 100 ml, all-glass
- Aeration: No aeration of the test solutions
- Renewal rate of test solution (frequency): at t=24h
- No. of organisms per vessel: 10 per vessel containing 80 ml medium
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- Biomass loading rate: 10 daphnia in 80 ml medium


TEST MEDIUM / WATER PARAMETERS: ISO, prepared in milli-RO water

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours photoperiod daily
- Light intensity: data not available


EFFECT PARAMETERS MEASURED:
- Immobility (including mortality): at 24 hours and 48 hours
- pH and dissolved oxygen: at the beginning, after 24 hours of exposure and at the end of the test, for all concentrations and the control(s)
- Temperature of medium: daily in one control vessel, beginning at the start of the test



TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8
- Range finding study:
- Test concentrations: 0, 0.1, 1, 10, 100 mg protein/L
- Results used to determine the conditions for the definitive study: 100% mortality at 100 mg/L, no mortality at the other test concentrations

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

81 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

other: protein content

Basis for effect:

mobility

Remarks on result:

other: 95% confidence interval between 64 and 116 mg/l. Note that the sharp decrease of oxygen contributes to the toxic stress of the daphnids.

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

1 015 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Remarks:

ALDOLASE (IUB 4.1.2.4)

Basis for effect:

mobility

Remarks on result:

other: Note that the sharp decrease of oxygen contributes to the toxic stress of the daphnids.

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

11 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: protein content

Basis for effect:

mobility

Remarks on result:

other: 95% confidence interval between 10 and 13 mg/l

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

141 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Remarks:

ALDOLASE (IUB 4.1.2.4)

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

7 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: protein content

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

88 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Remarks:

ALDOLASE (IUB 4.1.2.4)

Basis for effect:

mobility

Details on results:

- Mortality of control: no mortality was observed i nthe control groups

Results with reference substance (positive control):

- Results with reference substance valid? yes. The actual responses in this reference test with K2Cr207 are within the ranges of the expected responses at the different concentrations. Hence, the sensitivity of this batch of D. magna was in agreement with the historical data.
- EC50/LC50: the 24h-EC50 was 1.8 mg/l, the 48h-EC50 was 0.80 mg/l

Table 2: Acute immobilisation of daphnia after 24 and 48 hours in the final EC50-test

Nominal concentration		Vessel number	Number Daphnia exposed	Conc. Protein (mg/l) 24h	Response at 24h		Conc. Protein (mg/l) 48h	Response at 48h
Aldolase (mg/l)	Protein (mg/l)				number	%		number	%
0	0	A B	10 10		0 0	0 0		0 0	0 0
125	10	A B	10 10	5.7	0 0	0 0	5.3	0 0	0 0
225	18	A B	10 10	9.0	0 0	0 0	7.0	0 0	0 0
400	32	A B	10 10	18	0 0	0 0	17	9 10	90 10
700	56	A B	10 10	36	1 3	10 30	33	10 10	100 100
1250	100	A B	10 10	61	3 3	30 30	59	10 10	100 100
2250	180	A B	10 10	118	6 8	60 80	114	9 10	90 100

Validity criteria fulfilled:

yes

Remarks:

except for the oxygen concentration in the highest test concentration prepared at t=0 h and in the two highest test concentrations prepared at t= 24 h. This influence the results at t24, but not at t48 (conc. not taken into account).

Conclusions:

The 48h-EC50 was 11 mg protein per litre based on mean measured exposure concentrations. This corresponds to an ALDOLASE (IUB 4.1.2.4) concentration of 141 mg/l.

Executive summary:

The 48–hr-acute toxicity of ALDOLASE (IUB 4.1.2.4) to Daphnia magna was studied under semi-static conditions (according to OECD 202 guideline and GLP). Daphnids were exposed to control and test chemical at nominal concentrations of 0, 125, 225, 400, 700, 1250 and 2250 mg ALDOLASE (IUB 4.1.2.4) per litre (corresponding to 10, 18, 32, 56, 100 and 180 mg protein/l) for 48 hours. Mortality/immobilization and sublethal effects were observed at 24 and 48 hours.

The 24h-EC50 was 81 mg protein per litre based on measured exposure concentrations (95% confidence interval between 64 and 11 6 mg/l). This corresponds to an ALDOLASE (IUB 4.1.2.4) concentration of 101 5 mg/l. Note that the sharp decrease of oxygen contributes to the toxic stress of the daphnids.

The 48h-EC50 was 11 mg protein per litre based on mean measured exposure concentrations (95% confidence interval between 10 and 13 mg/l). This corresponds to an ALDOLASE (IUB 4.1.2.4) concentration of 141 mg/l.

 

Based on the results of this study, ALDOLASE would not be classified as dangerous to Daphnia magna under acute exposure conditions, according to EU criteria.

 

This study is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

Please refer to the analogue justification attached to IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

141 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Remarks:

Aldolase

Basis for effect:

mobility

Remarks on result:

other: 95% CL: 10 - 13 mg/L

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

11 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: protein content

Basis for effect:

mobility

Conclusions:

The key value retained for the assessment of the toxicity towards aquatic invertebrates of the target substance is an EC50 (48h) of 11 mg protein per litre based on mean measured exposure concentrations. This corresponds to an ALDOLASE (IUB 4.1.2.4) concentration of 141 mg/L. (OECD 202, Daphnia magna, RA to CAS 9026-97-5).

Executive summary:

Experimental data on the toxicity of Glutaryl Acylase IUBMB 3.5.1.93 (CAS 56645-46-6) on the toxicity towards aquatic invertebrates are not available. The toxicity was assessed using read across data from the analogue substance Aldolase enzyme concentrate; deoxyribose-phosphate aldolase IUB 4.1.2.4 (CAS 9026-97-5). This read-across is in accordance with Regulation (EC) No. 1907/2006 Annex XI, 1.5. Details on the read across justification are provided in section 13 of the IUCLID dossier.

The 48 h acute toxicity of ALDOLASE (IUB 4.1.2.4) to Daphnia magna was studied under semi-static conditions (according to OECD 202 guideline and GLP). Daphnids were exposed to control and test chemical at nominal concentrations of 0, 125, 225, 400, 700, 1250 and 2250 mg ALDOLASE (IUB 4.1.2.4) per litre (corresponding to 10, 18, 32, 56, 100 and 180 mg protein/L) for 48 hours. Mortality/immobilization and sublethal effects were observed at 24 and 48 hours.

The 24 h EC50 was 81 mg protein per litre based on measured exposure concentrations (95% confidence interval between 64 and 116 mg/L). This corresponds to an ALDOLASE (IUB 4.1.2.4) concentration of 1015 mg/L. Note that the sharp decrease of oxygen contributes to the toxic stress of the daphnids.

The 48 h EC50 was 11 mg protein per litre based on mean measured exposure concentrations (95% confidence interval between 10 and 13 mg/L). This corresponds to an ALDOLASE (IUB 4.1.2.4) concentration of 141 mg/L.

Based on the results of this study, ALDOLASE would not be classified as dangerous to Daphnia magna under acute exposure conditions, according to EU criteria.

This study is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.

In conclusion, this result is considered for Glutaryl Acylase IUBMB 3.5.1.93 (CAS 56645-46-6), too, based on the read-across conducted.

Description of key information

EC50 (48h) = 141 mg/L (i.e. 11 mg protein content/L) (Daphnia magna, OECD 202, measured, read-across from CAS 9026-97-5)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

141 mg/L

Additional information

Experimental data on the toxicity of Glutaryl Acylase IUBMB 3.5.1.93 (CAS 56645-46-6) on the toxicity towards aquatic invertebrates are not available. The toxicity was assessed using read across data from the analogue substance Aldolase enzyme concentrate; deoxyribose-phosphate aldolase IUB 4.1.2.4 (CAS 9026-97-5). This read-across is in accordance with Regulation (EC) No. 1907/2006 Annex XI, 1.5. Details on the read across justification are provided in section 13 of the IUCLID dossier.

The 48 h acute toxicity of ALDOLASE (IUB 4.1.2.4) to Daphnia magna was studied under semi-static conditions (according to OECD 202 guideline and GLP). Daphnids were exposed to control and test chemical at nominal concentrations of 0, 125, 225, 400, 700, 1250 and 2250 mg ALDOLASE (IUB 4.1.2.4) per litre (corresponding to 10, 18, 32, 56, 100 and 180 mg protein/L) for 48 hours. Mortality/immobilization and sublethal effects were observed at 24 and 48 hours.

The 24 h EC50 was 81 mg protein per litre based on measured exposure concentrations (95% confidence interval between 64 and 116 mg/L). This corresponds to an ALDOLASE (IUB 4.1.2.4) concentration of 1015 mg/L. Note that the sharp decrease of oxygen contributes to the toxic stress of the daphnids.

The 48 h EC50 was 11 mg protein per litre based on mean measured exposure concentrations (95% confidence interval between 10 and 13 mg/L). This corresponds to an ALDOLASE (IUB 4.1.2.4) concentration of 141 mg/L.

Based on the results of this study, ALDOLASE would not be classified as dangerous to Daphnia magna under acute exposure conditions, according to EU criteria.

This study is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.

In conclusion, this result is considered for Glutaryl Acylase IUBMB 3.5.1.93 (CAS 56645-46-6), too, based on the read-across conducted.