Registration Dossier

Diss Factsheets

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

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:
Not applicable, calculated value
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:
A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13. Petrotox is a well documented and peer reviewed model that is widely used across the petrochemicals industry. This substance fits within the criteria of the model and there are no reservations about the validity of the model runs. It is expected that this data is reliable with restrictions.
Qualifier:
no guideline followed
Principles of method if other than guideline:
The aquatic toxicity was estimated by a QSAR, the Petrotox computer model (v. 3.06). This model combines a partitioning model used to calculate the aqueous concentration of hydrocarbon components with the Target Lipid Model used to calculate acute and chronic toxicity of non-polar narcotic chemicals. Petrotox computes toxicity based on the summation of the aqueous-phase concentrations of hydrocarbon block(s) that represent a hydrocarbon substance and membrane-water partition coefficients (KMW) that describe the partitioning of the hydrocarbons between the water and organism
GLP compliance:
no
Remarks:
The data were calculated by a computer model.
Specific details on test material used for the study:
All data on input parameters are presented in Section 13 of IUCLID
Analytical monitoring:
not required
Details on sampling:
No data
Vehicle:
no
Details on test solutions:
No data
Test organisms (species):
Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)
Details on test organisms:
No data
Test type:
other: QSAR modelled data
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h
Post exposure observation period:
No data
Hardness:
No data
Test temperature:
No data
pH:
No data
Dissolved oxygen:
No data
Salinity:
No data
Nominal and measured concentrations:
No data
Details on test conditions:
No data
Reference substance (positive control):
not required
Key result
Duration:
72 h
Dose descriptor:
other: LL50
Effect conc.:
1.56 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: QSAR
Remarks:
Based on QSAR data
Details on results:
No data
Results with reference substance (positive control):
No data
Reported statistics and error estimates:
No data
Validity criteria fulfilled:
yes
Conclusions:
The estimated algal, 48-hr LL50 value for this substance is 1.56 mg/L based on growth inhibition.
Executive summary:

The aquatic toxicity was estimated using the Petrotox computer model, which combines a partitioning model used to calculate the aqueous concentration of hydrocarbon components as a function of substance loading with the Target Lipid Model used to calculate acute and chronic toxicity of non-polar narcotic chemicals. Petrotox computes toxicity based on the summation of the aqueous-phase concentrations of hydrocarbon block(s) that represent a hydrocarbon substance and membrane-water partition coefficients (KMW) that describe the partitioning of the hydrocarbons between the water and organism.

The estimated algal, 48-hr LL50 value for this substance is 1.56 mg/L based on growth inhibition.

Description of key information

A QSAR prediction using Petrotox v3.06 predicted an acute LL50 for algae of 1.56 mg/l, which is considered the key value for algae toxicity.

 

This is supported by two experimental studies on the read-across substance n-hexane which reported an ErL50 of 55 mg/L, EbL50 of 26 mg/L and a NOEL of 30 mg/L based on growth rate in one study and an EC50of 2.66% v/v of test substance. 

Key value for chemical safety assessment

Additional information