1-[2-(allyloxy)ethyl-2-(2,4-dichlorophenyl)-1H-imidazolium hydrogen sulphate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

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

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Justification for type of information:

Data from the related substance imazalil base is used to cover this endpoint. The justification for read across is attached in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: imazalil sulfate effect concentration

Remarks:

recalculated from imazalil base effect concentration

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: batch D7303, synthesized in own laboratories (97.6% purity)
- Expiration date of the lot/batch: not indicated
- Purity test date: 14 June 1988

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0.56, 1.0, 1.8, 3.2, 5.6 mg/l
- Sampling method: at the start, before and after each renewal and at the end of the test, samples of test medium were sampled from aquaria A to E
- Sample storage conditions before analysis: samples were frozen until the determination of the concentration of test substance

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: a stock solution containing 200 mg test substance per litre dilution water was prepared and used to prepare the test solutions
- Controls: yes

Test organisms (species):

Lepomis macrochirus

Details on test organisms:

TEST ORGANISM
- Common name: bluegills
- Strain: certified by the supplier to belong to the genus Lepomis
- Source: Osage catfisheries, Osage beach, Missouri
- Length at study initiation (length definition, mean, range and SD): 5.52 cm (standard deviation 0.44 cm, 95% confidence interval 5.35 - 5.68 cm)
- Weight at study initiation (mean and range, SD): 2.103 g (standard deviation 0.742g, 95% confidence interval 1.827 - 2.380 g)
- Method of breeding: Fish were immediately transferred to an aquarium with a permanent flow-through of tapwater. Fish were held at the test facilities for 8 months. During the first month fish were treated with an antibiotic and methylene-blue. No treatment was given during the next seven months. Two months before the start of the confirmatory test, the tap water was replaced by dilution water as used in the test and the permanent flow-through system was replaced by a recirculating filter system.

ACCLIMATION
- Acclimation period: 2 months
- Acclimation conditions (same as test or not): yes
- Health during acclimation (any mortality observed): the mortality during the two-months acclimation period was 0%, so that the lot was accepted

FEEDING DURING TEST
The fish were not fed the day preceding the test and during the whole test period.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

240 - 245 mg/l CaCO3

Test temperature:

22.3 - 23.1 °C

pH:

7.57 - 7.92

Dissolved oxygen:

7.4 - 9.2 mg/l O2

Salinity:

not applicable

Conductivity:

not applicable

Nominal and measured concentrations:

Nominal concentrations: 0.56, 1.0, 1.8, 3.2, 5.6 mg/l
Measured concentrations (t=0h): 0.44, 0.81, 1.52, 2.77, 5.69 mg/l
Measured concentrations (t=24h, before renewal): 0.44, 0.71, 1.36, 2.62, 5.16 mg/l
Measured concentrations (t=24h, after renewal): 0.42, 0.82, 1.46, 2.75, 5.56 mg/l
Measured concentrations (t=48h, before renewal): 0.46, 0.76, 1.40, 2.59, 5.45 mg/l
Measured concentrations (t=48h, after renewal): 0.46, 0.79, 1.49, 2.75, 6.16 mg/l
Measured concentrations (t=72h, before renewal): 0.44, 0.80, 1.43, 2.85, 5.97 mg/l
Measured concentrations (t=72h, after renewal): 0.49, 0.86, 1.53, 2.99, 5.84 mg/l
Measured concentrations (t=96h, end):0.45, 0.81, 1.30, 2.95, 5.99 mg/l

Details on test conditions:

TEST SYSTEM
- Test vessel: aquaria
- Material, size, headspace, fill volume: all-glass aquaria 16 litres, filled with 10 litres of dilution water
- Aeration: The aquaria were fitted out with an aeration device and covered with a glass pane to minimize evaporation and to prevent the fish from jumping out. The aquaria were continuously aerated.
- Renewal rate of test solution (frequency/flow rate): renewal took place every 24h
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dilution water was prepared in accordance with the OECD guideline 203
- Intervals of water quality measurement: at the start, before and after each renewal and at the end of the test

OTHER TEST CONDITIONS
- Photoperiod: 16h light - 8h dark
- Light intensity: fluorescent lamp (Philips 58W/33)

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Fish were inspected for lethality. Fish were considered dead if touching of the caudal peduncle produced no reaction. The fish were inspected after 2, 4, 24, 48, 72 and 96 hours.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.7
- Range finding study: yes
- Test concentrations: not indicated
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

4.04 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: No difference in behaviour could be observed between the control group and fish exposed to test substance concentrations of 0.56, 1 and 1.8 mg/l but some fish exposed to 1 and 1.8 mg imazalil per litre tended to stay at the bottom of the aquaria. All fish out of the 3.2 mg/l dosage group remained on the bottom of the aquarium and some of them showed signs of hyperventilation during a short period of time. Fish exposed to a test substance concentration of 5.6 mg/l were in a bad condition, remained on the bottom, lost their equilibrium and died all one after another in the course of the exposure period.
- Mortality of control: 0%

Reported statistics and error estimates:

Probit analysis, following the method of Finney, was applied to determine the LC50 - 96h and its 95% confidence limits. The homogeneity of the data was tested with chi-square statistics.

Validity criteria fulfilled:

yes

Conclusions:

A 96h semi-static mortality test with the bluegill (Lepomis macrochirus) was performed with the test substance Imazalil according to OECD guideline 203. The LC50 96h calculated on the basis of the measured concentrations was 4.04 mg imazalil / L. The results can be considered reliable without restrictions.

Reference 3

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: batch D7303, synthesized in own laboratories (97.6% purity)
- Expiration date of the lot/batch: not indicated
- Purity test date: 14 June 1988

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0.56, 1.0, 1.8, 3.2, 5.6 mg/l
- Sampling method: at the start, before and after each renewal and at the end of the test, samples of test medium were sampled from aquaria A to E
- Sample storage conditions before analysis: samples were frozen until the determination of the concentration of test substance

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: a stock solution containing 200 mg test substance per litre dilution water was prepared and used to prepare the test solutions
- Controls: yes

Test organisms (species):

Leuciscus idus

Details on test organisms:

TEST ORGANISM
- Common name: golden orfe
- Source: local hatchery (Huybrechts, Zoersel)
- Length at study initiation (length definition, mean, range and SD): 6.52 cm (standard deviation 0.31 cm, 95% confidence interval 6.40 - 6.63 cm)
- Weight at study initiation (mean and range, SD): 2.6 g (standard deviation 0.812 g, 95% confidence interval 2.297 - 2.902 g)

ACCLIMATION
- Acclimation period: 7 weeks
- Acclimation conditions (same as test or not): yes
- Health during acclimation (any mortality observed): Upon arrival at the test facilities, the fish were free from diseases and malformations. The mortality during the acclimation period recorded was < 5%, so that the lot was accepted.

FEEDING DURING TEST
The fish were not fed the day preceding the test and during the whole test period.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

14.7 - 15.7 mg/l CaCO3

Test temperature:

22.4 - 22.8 °C

pH:

7.90 - 8.29

Dissolved oxygen:

6.3 - 9.0 mg/l O2

Salinity:

not applicable

Conductivity:

not applicable

Nominal and measured concentrations:

Nominal concentrations: 0.56, 1.0, 1.8, 3.2, 5.6 mg/l
Measured concentrations (t=0h): 0.55, 0.83, 1.59, 2.73, 4.74 mg/l
Measured concentrations (t=24h, before renewal): 0.52, 0.88, 1.53, 2.66, 4.65 mg/l
Measured concentrations (t=24h, after renewal): 0.52, 0.85, 1.63, 2.74, - mg/l
Measured concentrations (t=48h, before renewal): 0.51, 0.92, 1.44, 2.67, - mg/l
Measured concentrations (t=48h, after renewal): 0.50, 0.98, 1.58, 2.67, - mg/l
Measured concentrations (t=72h, before renewal): 0.48, 0.65, 1.57, 2.87, - mg/l
Measured concentrations (t=72h, after renewal): 0.56, 0.94, 1.54, 2.32, - mg/l
Measured concentrations (t=96h, end): 0.44, 0.81, 1.44, 2.50, - mg/l

Details on test conditions:

TEST SYSTEM
- Test vessel: aquaria
- Material, size, headspace, fill volume: all-glass aquaria, 16l, filled with 10 litres of dilution water
- Aeration: The aquaria were fitted out with an aeration device and covered with a glass pane to minimize evaporation and to prevent the fish from jumping out. The aquaria were continuously aerated.
- Renewal rate of test solution (frequency/flow rate): renewal took place every 24h
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Dilution water was prepared in accordance with the DIN norm 38 412 - L 15. TAp water, dechlorinated over activated charcoal, was used.
- Intervals of water quality measurement: at the start, before and after each renewal and at the end of the test

OTHER TEST CONDITIONS
- Photoperiod: 16h light - 8h dark
- Light intensity: fluorescent lamp (Philips 58W/33)

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Fish were inspected for lethality. Fish were considered dead if touching of the caudal peduncle produced no reaction. The fish were inspected after 2, 4, 24, 48, 72 and 96 hours.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.7
- Range finding study : yes
- Test concentrations: not indicated
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

2.05 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: No difference in behaviour could be observed between the control group and fish exposed to test substance concentrations of 0.56 and 1 mg/l. Fish exposed to an imazalil concentration of 1.8 mg/l swam rather calmly. The surviving fish exposed to a test substance concentration of 3.2 mg/l were in bad condition and lost their equilibrium. Fish exposed to an imazalil concentration of 5.6 mg/l were immediately in bad condition and died within 1 hour.
- Mortality of control: 0%

Reported statistics and error estimates:

Probit analysis, following the method of Finney, was applied to determine the LC50 - 96h and its 95% confidence limits. The homogeneity of the data was tested with chi-square statistics.

Validity criteria fulfilled:

yes

Conclusions:

A 96h semi-static mortality test with the golden orfe (Leuciscus idus) was performed with the test substance Imazalil according to OECD guideline 203. The LC50 96h calculated was 2.05 mg imazalil / L. The results can be considered reliable without restrictions.

Reference 4

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: batch BEB191, synthesized in own laboratories (97.6% purity)
- Expiration date of the lot/batch: not indicated
- Purity test date: not indicated

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: Because the solubility of the free base was too low to prepare the required stock solutions, a sufficient amount was transformed to the sulphate salt and received the batch number PFA011 (purity 99.5%)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0.56, 1.00, 1.80, 3.20, 5.60 mg/l
- Sampling method: at the start of the test and at every 24-hour interval, samples of test medium were sampled from aquaria A to E
- Sample storage conditions before analysis: samples were frozen until analysis

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Imazalil from batch BEB191, synthesized in own laboratories and with a purity of 97.6%, was used. Because the solubitliy of the free base was too low to prepare the required stock solutions, a sufficient amount was transformed to the sulphate salt and received the batch number PFA011. The purity of the latter was 99.5%
- Controls: yes

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: rainbow trout
- Strain: certified by the supplier to belong to the genus Salmo
- Source: local hatchery (Wijnant-Meussen, Voeren)
- Length at study initiation (length definition, mean, range and SD): 4.6 cm (standard deviation 0.23 cm, 95% confidence interval 4.50 - 4.67 cm)
- Weight at study initiation (mean and range, SD): 1.13 g (standard deviation 0.23 g, 95% confidence interval 1.05 - 1.22 g)

ACCLIMATION
- Acclimation period: 48 hours
- Acclimation conditions (same as test or not): yes
- Health during acclimation (any mortality observed): Upon arrival at the test facilities, the fish were free from diseases and malformations. The mortality during the acclimation period recorded after a settling-in period of 48 hours was < 5%, so that the lot was accepted.

FEEDING DURING TEST
The fish were not fed the day preceding the test and during the whole test period.

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

176.4 mg/l CaCO3

Test temperature:

12.7 - 13.3 °C

pH:

8.5 - 8.20

Dissolved oxygen:

75% O2

Salinity:

not applicable

Conductivity:

not applicable

Nominal and measured concentrations:

Nominal concentrations: 0.56, 1.0, 1.8, 3.2, 5.6 mg/l
Measured concentrations (0h): 0.54, 1.08, 1.57, 2.57, 4.14 mg/l
Measured concentrations (24h): 0.52, 0.89, 1.56, 2.67, 4.42 mg/l
Measured concentrations (48h): 0.48, 0.80, 1.35, 1.98, * mg/l
Measured concentrations (72h): 0.52, 0.87, 1.46, 2.55, * mg/l
Measured concentrations (96h): 0.52, 0.89, 1.58, 2.62, * mg/l

* all fish dead

Details on test conditions:

TEST SYSTEM
- Test vessel: aquaria
- Material, size, headspace, fill volume: all-glass aquaria with a capacity of 40 l
- Aeration: The aquaria were fitted out with an aeration device and covered with a glass pane to prevent the fish from jumping out. The test media were continually aerated.
- Renewal rate of test solution (frequency/flow rate): 140 ml/min (139 ml tap water and 1 ml stock solution)
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Tap water, dechlorinated over activated charcoal, was used as dilution water
- Culture medium different from test medium: no
- Intervals of water quality measurement: at the start and every 24-hour interval

OTHER TEST CONDITIONS
- Photoperiod: 16h light - 8h dark
- Light intensity: fluorescent lamp Philips 58W/33

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Fish were observed for lethality. Fish were considered dead if touching of the caudal peduncle produced no reaction. The fish were inspected at the beginning of the test and after 24, 48, 72 and 96 hours.

TEST CONCENTRATIONS
- Spacing factor for test concentrations:

- Range finding study : yes
- Test concentrations: not indicated
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

1.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% confidence interval: 1.48 - 1.48 mg/l

Details on results:

- Behavioural abnormalities: Up to 1.8 mg Imazalil per litre, there was no significant effect on the behaviour of the fish in comparison with the control group. Fish subjected to 3.2 mg Imazalil per litre were in a bad condition and, with the exception of one fish, died one after another in the course of the exposure period. Fish out of the 5.6 mg/l doage group were immediately in a bad condition. Five fish died within 2 hours of exposure. The remaining fish died within 24 hours of exposure.
- Mortality of control: 0%

Reported statistics and error estimates:

Probit analysis, following the method of Finney, was applied to determine the LC50 - 96h (median lethal concentration after 96h) and its 95% confidence limits. the homogeneity of the data was tested with chi-square statistics.

Validity criteria fulfilled:

yes

Conclusions:

A 96h flow-through mortality test with the rainbow trout (Salmo gairdneri) was performed with the test substance Imazalil according to OECD guideline 203. The LC50 96h calculated was 1.5 mg imazalil / l. The results of the test can be considered reliable without restrictions.

Description of key information

Three studies were performed on imazalil (source read across substance). Acute toxicity values of imazalil ranged from 1.5 mg/L up to 5.6 mg/L. The lowest LC50 was taken further for environmental risk assessment which corresponds to 2.0 mg imazalil sulphate/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

2 mg/L