Star anise, Illicium verum, ext.

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

Type of information:

mixture rules calculation

Adequacy of study:

key study

Study period:

03 March 2021

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2021

Report date:

2021

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

tested according to the Water Accommodated Fraction (WAF) approach

Principles of method if other than guideline:

The ACUTE TOXICITY TO FISH (96-HOUR LL50) was determined using iSafeRat® calculation method adapted for a mixture of compounds with the Mechanism of Action (MechoA) in question (MechoA 1.1, i.e. non-polar narcosis). This calculation method predicts the endpoint value which would be expected when testing the substance under experimental conditions in a laboratory following the Guideline for Testing of Chemicals No. 203, "Fish Acute Toxicity Test", referenced as Method C.1 of Commission Regulation No. 440/2008 adapted for testing of a mixture using the WAF method. The criterion predicted was the median lethal loading rate of the mixture LL50 (Median Lethal Loading), a statistically derived loading rate which is expected to cause mortality in 50% of test animals within a period of 96 hours. The calculation method is based on QSAR model predictions for acute toxicity of constituents. The QSAR model used has been validated to be compliant with the OECD recommandations for QSAR modeling. This model is based on validated data for a training set of 67 chemicals derived from 96-hour test on fish, for which the concentrations of the test item had been determined by chemical analyses over the test period. Further to this the lethal loading rate of the WAF is determined by using a series of calculation steps using phase equilibrium thermodynamics and excluding the non-bioavailable fraction, this approach is based on validated data derived from 96-hour tests on fish, for which the concentrations of the test item had been determined by chemical analyses over the test period.

GLP compliance:

no

Remarks:

calculation method

Test material

Test material information

Constituent 1

Reference substance name:

Star anise, Illicium verum, ext.

EC Number:

283-518-1

EC Name:

Star anise, Illicium verum, ext.

Cas Number:

84650-59-9

Molecular formula:

NA

IUPAC Name:

1-methoxy-4-[(1E)-prop-1-en-1-yl]benzene

Test material form:

liquid

Sampling and analysis

Analytical monitoring:

no

Details on sampling:

not applicable

Test solutions

Vehicle:

no

Details on test solutions:

not applicable

Test organisms

Test organisms (species):

other: Danio rerio, Oncorhynchus mykiss, Lepomis macrochirus, Pimephales promelas, Oryzias latipes, Leuciscus idus

Details on test organisms:

No difference in terms of toxic mechanism of action between fish freshwater species is expected. Any observed differences may be attributed to lifestyle related parameters (e.g. relative differences in storage lipid content between species) and relative duration of study versus bodysize rather than to a specific toxic mechanism causing species differences.

Study design

Test type:

other: calculation method based on QSAR model predictions

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Remarks on exposure duration:

Only results from a test duration of 96 hours were included in the training set of the model.

Post exposure observation period:

None

Test conditions

Hardness:

The QSAR model is based on data from studies performed at acceptable hardness to ensure control survival.

Test temperature:

The temperatures varied from approximately 14 to 25 °C depending on the fish species used to construct the algorithm. While it is recognized that this may contribute to some extent to the variability of the LC50 values found in experimental data, KREATiS has not observed a clear trend suggesting that normalization to temperature would necessarily improve the algorithm (say for trout as opposed to warm water species like fathead minnow for example) for monoconstituents.

pH:

Test results were taken from studies with measured pHs between 6.0 - 8.5.

Dissolved oxygen:

The QSAR model is based on data from reliable studies performed at acceptable oxygen concentrations (generally >60%).

Salinity:

Not applicable

Conductivity:

Not applicable

Nominal and measured concentrations:

Studies were used for QSAR model development only where sufficient evidence was presented to determine that the stubstance was stable under test conditions (i.e. maintened within ± 20 % of the nominal) or, if not, the result was based on measured concentrations as geometric mean.

Details on test conditions:

Studies with various test designs were selected for QSAR model development. Preferentially results from semi-static experiments with daily renewal of test solutions and the control or from flow-through tests were used. However, for stable, low volatility substances a static design was accepted (preferably accompanied by analytical measurements over the study period). For suspected volatile substances only tests performed in closed vessels were accepted unless accompanying analytical monitoring proved such a design was not necessary.

Reference substance (positive control):

not required

Results and discussion

Effect concentrations

Key result

Duration:

96 h

Dose descriptor:

LL50

Effect conc.:

22 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

mortality (fish)

Remarks on result:

not determinable

Results with reference substance (positive control):

Not applicable

Any other information on results incl. tables

Sublethal observations / clinical signs:

Prior Analysis of the MechoA constituents of the test item.

The calculation method used in this study is based on toxic additivity principle. That means the toxic parts of each constituent are added up. Therefore the constituents considered within the mixture should act with a similar MechoA. The MechoA of the consituents are determined using the methodology described by Bauer et al. (2018) and reported in the Table below.

 

Table. MechoA of the constituents.

constituents	MechoA	Description
const1	1.1	non-polar narcotic
const2	1.1	non-polar narcotic
const3	1.1	non-polar narcotic
const4	1.1	non-polar narcotic
const5	1.1	non-polar narcotic
const6	1.1	non-polar narcotic
const7	1.1	non-polar narcotic
const8	3.1	reactive compound, as hard elecrtrophile
const9	1.1	non-polar narcotic

Only one minor constituent (<<1%), const8, does not act with narcosis-based MechoA. We consider the assumption that the constituents of the test item act with the same general MechoA is still valid. Therefore the calculation method is applicable.

 

Posterior Analysis of the WAF composition at the toxicity value (E/LL₅₀) for the typical composition.

The Pareto chart within the study report hightlights the importance of each constituent in order to explain the global toxicity of the WAF of the mixture for the toxic loading rate (E/LL₅₀). It indicates const1 explains ca. 90% of the test item toxicity. Despite the reactive MechoA of const8, the toxic impact is negligeable due to its small amount in the test item.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The ACUTE TOXICITY TO FISH (96-HOUR LL50) of the test item has been determined using the iSafeRat® calculation method for mixtures tested according to the Water Accomodated Fraction (WAF) approach. Each constituents of the test item which have been considered fall within the applicability domain of the model used to determine their individual ACUTE TOXICITY TO FISH (96-HOUR LC50). Moreover, more than 95% of the constituents of the test item act a non-polar narcotic MechoA. Only one minor constituent was identified with another MechoA. However, its toxic impact has been demonstrated to be negligeable. Therefore the calculation method is still applicable and the final result for the test item can be considered valid for use in risk assessment and classification and labelling.

Executive summary:

The ACUTE TOXICITY TO FISH (96-HOUR LL50) was determined using iSafeRat® calculation method adapted for a mixture of compounds with the Mechanism of Action (MechoA) in question (MechoA 1.1, i.e. non-polar narcosis). This calculation method predicts the endpoint value which would be expected when testing the substance under experimental conditions in a laboratory following the Guideline for Testing of Chemicals No. 203, "Fish Acute Toxicity Test", referenced as Method C.1 of Commission Regulation No. 440/2008 adapted for testing of a mixture using the WAF method. The criterion predicted was the median lethal loading rate of the mixture LL50 (Median Lethal Loading), a statistically derived loading rate which is expected to cause mortality in 50% of test animals within a period of 96 hours. The calculation method is based on QSAR model predictions for acute toxicity of constituents. The QSAR model used has been validated to be compliant with the OECD recommandations for QSAR modeling. This model is based on validated data for a training set of 67 chemicals derived from 96-hour test on fish, for which the concentrations of the test item had been determined by chemical analyses over the test period. Further to this the lethal loading rate of the WAF is determined by using a series of calculation steps using phase equilibrium thermodynamics and excluding the non-bioavailable fraction, this approach is based on validated data derived from 96-hour tests on fish, for which the concentrations of the test item had been determined by chemical analyses over the test period.

 

Each constituents of the test item which have been considered fall within the applicability domain of the model used to determine their individual ACUTE TOXICITY TO FISH (96-HOUR LC50). Moreover, more than 95% of the constituents of the test item act a non-polar narcotic MechoA. Only one minor constituent was identified with another MechoA. However, its toxic impact has been demonstrated to be negligeable. Therefore the calculation method is still applicable and the final result for the test item can be considered valid for use in risk assessment and classification and labelling.

 

The ACUTE TOXICITY TO FISH (96-HOUR LC50) of the test item was predicted as 22 mg/L.

95% confidence interval (α = 0.05): not determined.