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

Sediment toxicity

Link to relevant study record(s)

Reference

Endpoint:

sediment toxicity: long-term

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

up to 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 sediment and application:

N/A

Test organisms (species):

Lumbriculus variegatus

Details on test organisms:

N/A

Study type:

other: QSAR

Test type:

other: QSAR

Water media type:

other: QSAR

Type of sediment:

not specified

Remarks:

QSAR

Limit test:

no

Post exposure observation period:

N/A

Hardness:

N/A

Test temperature:

N/A

pH:

N/A

Dissolved oxygen:

N/A

Salinity:

N/A

Ammonia:

N/A

Conductivity:

N/A

Nominal and measured concentrations:

N/A

Details on test conditions:

N/A

Reference substance (positive control):

no

Remarks:

QSAR

Key result

Duration:

28 d

Dose descriptor:

other: LL50

Effect conc.:

100.47 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other:

Remarks:

Result from QSAR

Key result

Duration:

28 d

Dose descriptor:

other: NOELR

Effect conc.:

19.247 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks:

biomass

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 estimated LL50 for this substance is 100.470 mg/kg sediment dw and the NOELR was 19.247 mg/kg sediment dw.

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 sediment and soil organisms. The TLM-EqP predicted effect values (28-days) for this substance were 100.470 and 19.247 mg/kg sediment dw for short-term (LL₅₀) and long-term effects (NOELR), 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 L. variegatus. The calculated LL₅₀ is 100.47 mg/kg sediment dw and NOELR is 19.247 mg/kg sediment dw.

Key value for chemical safety assessment

EC50 or LC50 for freshwater sediment:

100.47 mg/kg sediment dw

EC10, LC10 or NOEC for freshwater sediment:

19.247 mg/kg sediment dw