Pepper (Piper), P. nigrum, ext.

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

calculation (if not (Q)SAR)

Remarks:

Estimated by calculation

Adequacy of study:

key study

Study period:

2017-02-10 to 2017-02-10

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

yes

Remarks:

calculation method

Principles of method if other than guideline:

The acute toxicity to aquatic algae was determined using a validated QSAR for the Mode of Action in question. The first step of the iSafeRat mixture toxicity calculation employs phase equilibrium thermodynamics in order to determine the concentrations of each constituent within the WAF. This fraction equates to the analysable fraction of a WAF study.
Within the WAF, the constituents also partition between themselves further reducing the bioavailable fraction and thus the toxicity of the mixture compared to the individual constituents. In the calculation the second step is to remove this non-bioavailable fraction.
The final step is to determine the truly bioavailable fraction of the WAF per constituent. The ErC50s of each constituent are already known from literature or calculated using the iSafeRat QSAR model. Each value and calculation has been included as a supporting study in the IUCLID. An additivity approach (based on Chemical Activity of each constituent) is used in order to calculate the Effective Loading rate of the WAF.
The method has been validated using data derived from 72-hour ErC50 tests on aquatic algae, for which the concentrations of the test item had been determined by chemical analyses over the test period. Further to this the effective loading rate of the WAF is determined by using a series of calculation steps using phase equilibrium thermodynamics and excluding the non-bioavailable fraction.

GLP compliance:

not specified

Specific details on test material used for the study:

Not applicable

Analytical monitoring:

not required

Details on sampling:

not applicable

Vehicle:

no

Details on test solutions:

not applicable

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

not applicable

Test type:

other: calculation method

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Remarks on exposure duration:

72h-ErL50 (effective loading rate of WAF)

Post exposure observation period:

not applicable

Hardness:

Hardness is not a necessary component of the WAF calculation

Test temperature:

The Temperature is not a necessary component of the WAF calculation

pH:

The pH is not a necessary component of the WAF calculation

Dissolved oxygen:

The oxygen concentration is not a necessary component of the WAF calculation

Salinity:

Salinity is not a necessary component of the WAF calculation.

Nominal and measured concentrations:

The calculation determines measured concentrations

Details on test conditions:

calculation method

Reference substance (positive control):

not required

Duration:

72 h

Dose descriptor:

other: ErL50

Remarks:

effective loading rate of WAF

Effect conc.:

9.6 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other:

Remarks:

Based on the typical composition provided by the supplier of the substance

Details on results:

not applicable

Results with reference substance (positive control):

not applicable

Reported statistics and error estimates:

not applicable

At this loading rate, the expected concentrations of each constituent in the mixture (based on thermodynamic calculation) are as follows:

constituents	concentration in the WAF (mg.L^-1)
β-caryophyllene	0.020
limonene	0.96
sabinene	1.0
β-pinene	0.74
α-pinene	0.30
Δ-3-carene	0.20
α-copaene	0.0010
Δ-elemene	0.0012
β-bisabolene	0.00081
β-phellandrene	0.19
Δ-cadinene	0.0015
myrcene	0.083
α-caryophyllene	0.00065
α-thujene	0.11
α-phellandrene	0.068

Validity criteria fulfilled:

yes

Conclusions:

72h-ErL50 for typical composition of Pepper Black Oil = 9.6 mg test item/L.

Executive summary:

Pepper Black Oil is a Natural Complex Substance (UVCB) with a well-defined composition. Its acute toxicity to aquatic algae has been investigated using an in-house calculation method that replaces an OECD 201 study and guideline for Testing of Chemicals No. 23 (i.e. WAF conditions). The “typical” composition proposed by the Lead registrant has been investigated.

The first step of the iSafeRat mixture toxicity calculation employs phase equilibrium thermodynamics in order to determine the concentrations of each constituent within the WAF. This fraction equates to the analyzable fraction of a WAF study.

Within the WAF, the constituents also partition between themselves further reducing the bioavailable fraction and thus the toxicity of the mixture compared to the individual constituents. In the calculation the second step is to remove this non-bioavailable fraction.

The final step is to determine the truly bioavailable fraction of the WAF per constituent. The ErC50s of each constituent are already known from literature or predicted using the iSafeRat QSAR model. Each value has been included as a supporting study in the IUCLID. An additivity approach (based on Chemical Activity of each constituent) is used in order to calculate the Effective Loading rate of the WAF.

Using this approach, the 72-h ErL50 was 9.6 mg test material/L for the typical composition of Pepper Black Oil. ErL50 was based on growth rate.

Based on the results of this study, Pepper Black oil would not be classified as acute 1 to aquatic organisms in accordance with the classification of the CLP.

This toxicity study is acceptable and can be used for that endpoint.

 

Results Synopsis

Test Type: Calculation method

ErL50: 9.6 mg test material/L for typical composition

Description of key information

72h-ErL50 for typical composition of Pepper Black Oil  = 9.6 mg test item/L.

Based on the results of this study, Pepper Black oil would not be classified as acute 1 to aquatic organisms in accordance with the classification of the CLP.

Key value for chemical safety assessment

EC50 for freshwater algae:

9.6 mg/L

Additional information

The acute toxicity to aquatic algae of the UVCB Pepper Black Oil has been investigated using a reliable in-house calculation method that replaces an OECD 201 study and guideline for Testing of Chemicals No. 23 (i.e. WAF conditions). The “typical” composition proposed by the Lead registrant has been investigated.

The first step of the iSafeRat mixture toxicity calculation employs phase equilibrium thermodynamics in order to determine the concentrations of each constituent within the WAF. This fraction equates to the analyzable fraction of a WAF study. Within the WAF, the constituents also partition between themselves further reducing the bioavailable fraction and thus the toxicity of the mixture compared to the individual constituents. In the calculation the second step is to remove this non-bioavailable fraction. The final step is to determine the truly bioavailable fraction of the WAF per constituent. The ErC50s of each constituent are already known from literature or predicted using the iSafeRat QSAR model. Each value has been included as a supporting study in the IUCLID. An additivity approach (based on Chemical Activity of each constituent) is used in order to calculate the Effective Loading rate of the WAF.

Based on the results of this study, Pepper Black oil would not be acutely toxic to aquatic organisms in accordance with the classification of the CLP.

This toxicity study is acceptable and can be used for that endpoint.