3a,4,7,7a-tetrahydro-4,7-methanoindene

Toxicity to terrestrial plants

Link to relevant study record(s)

Reference

Endpoint:

toxicity to terrestrial plants: long-term

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

2017

Reliability:

2 (reliable with restrictions)

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 justification

Qualifier:

no guideline required

Principles of method if other than guideline:

The endpoint calculated is the LL50, EL50, and NOELR.
The narcosis target lipid model was developed to predict the toxicity of chemicals to aquatic organisms that act via narcosis. It is based on the hypothesis that target lipid is the site of toxic action within the organism, that octanol is the appropriate surrogate, and that target lipid has the same physical–chemical properties in all organisms.
The approach describes:
• The theory and how to predict the acute toxicity to these organisms;
• Development of an Acute to Chronic ratio [ACR] for only hydrocarbons and for 29 data points.

GLP compliance:

no

Remarks:

QSAR

Specific details on test material used for the study:

A logkow of 2.78 was used as input for the prediction

Analytical monitoring:

not required

Remarks:

QSAR

Details on sampling:

N/A

Vehicle:

no

Remarks:

QSAR

Details on preparation and application of test substrate:

N/A

Species:

Avena sativa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

N/A

Species:

Brassica rapa

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

N/A

Test type:

other: QSAR

Study type:

other: QSAR

Substrate type:

other: QSAR

Limit test:

no

Remarks:

N/A

Post exposure observation period:

N/A

Test temperature:

N/A

pH:

N/A

Moisture:

N/A

Details on test conditions:

N/A

Nominal and measured concentrations:

N/A

Reference substance (positive control):

no

Remarks:

QSAR

Key result

Species:

Avena sativa

Duration:

14 d

Dose descriptor:

other: LL50

Effect conc.:

253.568 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Remarks on result:

other:

Remarks:

Result from QSAR

Key result

Species:

Avena sativa

Duration:

21 d

Dose descriptor:

other: NOELR

Effect conc.:

48.576 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks on result:

other:

Remarks:

Result from QSAR

Key result

Species:

Brassica rapa

Duration:

14 d

Dose descriptor:

other: LL50

Effect conc.:

163.717 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Remarks on result:

other:

Remarks:

Result from QSAR

Key result

Species:

Brassica rapa

Duration:

21 d

Dose descriptor:

other: NOELR

Effect conc.:

31.363 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks on result:

other:

Remarks:

Result from QSAR

Details on results:

N/A

Results with reference substance (positive control):

N/A

Reported statistics and error estimates:

N/A

N/A

Validity criteria fulfilled:

not applicable

Remarks:

QSAR

Conclusions:

The TLM-EqP predicted effect values for the substance were 253.568 and 48.576 mg/kg soil dw for short-term (14-day LL50) and long-term effects (21-day NOELR) to Avena sativa, respectively. The TLM-EqP predicted effect values for the substance were 163.717 and 31.363 mg/kg soil dw for short-term (14-day LL50) and long-term effects (21-day NOELR) to Brassica rapa, respectively.

Executive summary:

The registered substance is highly volatile which complicates environmental testing. Therefore, a modeling framework is needed to account for the bioavailability of the substance to perform read-across and data gap filling. The TLM-EqP modeling has been validated as a suitable method for predicting effect values in terrestrial plants. The TLM-EqP predicted effect values for the substance were 253.568 and 48.576 mg/kg soil dw for short-term (14-day LL₅₀) and long-term effects (21-day NOELR) to Avena sativa, respectively. The TLM-EqP predicted effect values for the substance were 163.717 and 31.363 mg/kg soil dw for short-term (14-day LL₅₀) and long-term effects (21-day NOELR) to Brassica rapa, respectively.

The prediction is considered to fall within the model domain

Description of key information

TLM QSAR modelling was used to estimate the LC₅₀ and EC₁₀ values towards terrestrial plants. The calculated LL₅₀ for A. sativa is 253.568 mg/kg soil dw and NOELR is 48.576 mg/kg soil dw. The calculated LL50 for B. rapa is 163.717 mg/kg soil dw and NOELR is 31.363 mg/kg soil dw.

The lowest value was used for chemical safety assessment.

Key value for chemical safety assessment

Short-term EC50 or LC50 for terrestrial plants:

163.717 mg/kg soil dw

Long-term EC10, LC10 or NOEC for terrestrial plants:

31.363 mg/kg soil dw