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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Ecotoxicological information

Toxicity to microorganisms

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Administrative data

Link to relevant study record(s)

Reference
Endpoint:
activated sludge respiration inhibition testing
Type of information:
(Q)SAR
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: This summary has a reliability of 2 because the results are estimated using a computer model that is appropriate for use with this petroleum substance.
Principles of method if other than guideline:
The aquatic toxicity was estimated by a QSAR, the PETROTOX computer model (v 4.0). 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. For model description and justification of QSAR prediction: see field 'Justification for type of information'.
Analytical monitoring:
not required
Test organisms (species):
activated sludge
Test type:
other: QSAR modelled data
Water media type:
freshwater
Limit test:
no
Total exposure duration:
15 h
Key result
Duration:
15 h
Dose descriptor:
other: EL50
Effect conc.:
> 1 000 mg/L
Nominal / measured:
estimated
Conc. based on:
other: QSAR prediction
Basis for effect:
inhibition of total respiration
Remarks on result:
other: QSAR predicted value
Key result
Duration:
15 h
Dose descriptor:
other: EL10
Effect conc.:
> 1 000 mg/L
Nominal / measured:
estimated
Conc. based on:
other: QSAR prediction
Basis for effect:
inhibition of total respiration
Remarks on result:
other: ACR 5.22 (McGrath et al., 2018)
Remarks:
QSAR predicted value
Details on results:
Chronic endpoints were estimated using typical acute-to-chronic ratio of 5.22 (McGrath et al., 2018).
Validity criteria fulfilled:
yes
Conclusions:
The PETROTOX-estimated freshwater 15-h EL50 (Effect Loading Rate 50%) value for activated sludge is >1000 mg/L based on inhibition of total respiration, and the PETROTOX-estimated freshwater 15-h EL10 (Effect Loading Rate 10%) value for activated sludge is >1000 mg/L based on inhibition of total respiration.
Executive summary:

The aquatic toxicity was estimated using the PETROTOX computer model (v4.0), 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 nonpolar 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 partitioning coefficients (KMW) that describe the partitioning of the hydrocarbons between the water and organism.

The PETROTOX-estimated freshwater 15-h EL50 (Effect Loading Rate 50%) value for activated sludge is >1000 mg/L based on inhibition of total respiration, and the PETROTOX-estimated freshwater 15-h EL10 (Effect Loading Rate 10%) value for activated sludge is >1000 mg/L based on inhibition of total respiration.

Description of key information

The registered substance is a complex mixture whose constituents within the mixture have variable physicochemical properties. Therefore, a modeling framework is needed to account for the bioavailability of the constituents in the mixture, which was then used to predict the toxicity of the substance as a whole. A computer-based program, PETROTOX (v4.0), was used to calculate aquatic toxicity. The program is an extension of the three-phase partitioning (to calculate the partitioning of constituents in air, water, and non-aqueous phase liquid phases) and toxicity models used to predict the toxicity of complex substances, and incorporates the Target Lipid Model (TLM), which has been validated for applications to individual narcotic chemicals and mixtures. Composition information is entered as separate hydrocarbon blocks according to carbon number range and chemical classes, which comprise the substance.Representative constituents input to model located in the attachment "PETRORISK and PETROTOX block allocation" in Section 13.2 of IUCLID.

Full justifications for these QSAR are presented in 'Attached justification' within the associated endpoint records, but in brief these are justified because:

-the results are obtained from a QSAR model whose scientific validity has been established

-petroleum substances fall within the applicability domain of the QSAR model

-results are adequate for the purposes of risk assessment

-adequate and reliable documentation is provided

Key value for chemical safety assessment

Additional information