Boswellia papyrifera, ext.

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

From 2019-01-04 to 2019-01-04

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

Justification for type of information:

See attached documents for full details.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Deviations:

yes

Remarks:

Calculation method

Principles of method if other than guideline:

The growth inhibition of algae was determined using a validated calculation method for the Mechanism of Action (MechoA) in question (MechoA 1.1, i.e. non-polar narcosis). The QSAR model is based on validated data from a training set of 40 chemicals derived from 72-hour test on algae, for which the concentrations of the test item had been determined by chemical analyses over the test period.

GLP compliance:

no

Specific details on test material used for the study:

None.

Analytical monitoring:

no

Details on sampling:

Not applicable.

Vehicle:

no

Details on test solutions:

Not applicable.

Test organisms (species):

other: algae spp.

Details on test organisms:

Results from the following species were used in the regression:
- Desmodesmus subspicatus
- Pseudokirchneriella subcapitata
- Scenedesmus quadricauda

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:

Not applicable.

Test temperature:

Not applicable.

pH:

Not applicable.

Dissolved oxygen:

Not applicable.

Salinity:

Not applicable.

Conductivity:

Not applicable.

Nominal and measured concentrations:

Not applicable.

Details on test conditions:

Calculation method.

Reference substance (positive control):

not required

Key result

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

15 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other:

Remarks:

based n typical composition

Details on results:

Not applicable.

Results with reference substance (positive control):

Not applicable.

Reported statistics and error estimates:

Not applicable.

Determination of the Analytically Measurable Aqueous Phase (AMAP).

Using the model, the specific concentration of each constituent in the WAF can be accurately determined at any loading rate taking into account the original composition of the mixture and the new corrected limit of solubility of

each constituent. The sum of these concentrations, the AMAP, is equivalent to the concentration of all constituents that would be measured in a WAF test. For a given loading rate, the loaded concentration of each constituent is

compared to its respective solubility limit. If one is higher than the solubility limit then it is considered that the concentration of the constituent will be equal to its solubility limit. If lower, the true loading concentration is considered. Provided this adapted water solubility limits for each consitutents. analytically measurable concentrations in aqueous solutions expected from known WAF loading rates of characterised mixtures can be calculated. The AMAP expected at the ErL50 is given below:

Analytically Measured Aqueous Phase (AMAP) calculated at the predicted ErL₅₀.

constituents	concentration in the WAF (mg.L^-1)
Constituent 1	8.30
Constituent 2	0.903
Constituent 3	0.108
Constituent 4	0.0945
Constituent 5	3.32E-05
Constituent 6	6.41E-06
Constituent 7	0.126
Constituent 8	5.31E-03
Constituent 9	0.185
Constituent 10	6.84E-04

Validity criteria fulfilled:

yes

Conclusions:

The following toxicity value has been estimated for the registered substance: 72h-ErL50 = 15 mg/L.

Executive summary:

A calculation method was used to predict the inhibition of algal growth exposed to the test item OLIBANUM OIL (Bowsellia papyrifera), using the WAF method. 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. 201, "Freshwater Alga and Cyanobacteria, Growth Inhibition Test", referenced as Method C.3 of Commission Regulation No. 440/2008 (2) adapted for testing of a mixture using the WAF method. The criterion measured was the median effective loading rate of the mixture ErL50 (Median Effective Loading for specific growth rate), a statistically derived loading rate which is expected to cause 50% inhibition of intrinsic rate of growth of the test system within a period of 72 hours.

The result below is the toxicity value anticipated during a 72-hour ErL₅₀study on algae based on the composition of OLIBANUM OIL (Bowsellia papyrifera).

The 72-hour ErL₅₀is calculated as follows:

Composition	Time (h)	ErL50(mg test item.L^-1)
typical	72	15

 

 

Description of key information

The following toxicity value has been found for the registered substance:72h-ErL50 = 15 mg/L.

Key value for chemical safety assessment

EC50 for freshwater algae:

15 mg/L

Additional information

For that endpoint, one study with the registered substance was available. Indeed, the toxicity to aquatic algae of the registered substance 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).

A typical composition of the substance has been investigated.The algorithm used for the purpose of this study is based on a QSAR model which has been validated to be compliant with the OECD recommendations for QSAR modeling (OECD, 2004).

A calculation method was used to predict the inhibition of algal growth exposed to the test item OLIBANUM OIL (Bowsellia papyrifera), using the WAF method. 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. 201, "Freshwater Alga and Cyanobacteria, Growth Inhibition Test", referenced as Method C.3 of Commission Regulation No. 440/2008 (2) adapted for testing of a mixture using the WAF method. The criterion measured was the median effective loading rate of the mixture ErL50 (Median Effective Loading for specific growth rate), a statistically derived loading rate which is expected to cause 50% inhibition of intrinsic rate of growth of the test system within a period of 72 hours.

The result below is the toxicity value anticipated during a 72-hour ErL₅₀study on algae based on the composition of OLIBANUM OIL (Bowsellia papyrifera).

The 72-hour ErL₅₀is calculated as follows:

The 72-hour ErL₅₀is calculated as follows:

Composition	Time (h)	ErL50(mg test item.L^-1)
typical	72	15