Registration Dossier

Administrative data

Endpoint:
toxicity to microorganisms, other
Remarks:
QSAR
Type of information:
(Q)SAR
Adequacy of study:
key study
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 limited documentation / justification
Justification for type of information:
The target lipid model (TLM) is a framework that relates toxicity to the physicochemical properties of a nonpolar organic constituent. It 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.

Data source

Referenceopen allclose all

Reference Type:
publication
Title:
Refinement and validation of TLM-derived HC5 values. Independent review.
Author:
McGrath JA, Di Toro DM, Fanelli CJ
Year:
2015
Bibliographic source:
HDR, Mahwah, NJ
Reference Type:
publication
Title:
Application of the narcosis target lipid model to algal toxicity and deriving predicted no effect concentrations.
Author:
McGrath, J.A., T.F. Parkerton, and D.M. Di Toro
Year:
2004
Bibliographic source:
Environ. Toxicol. Chem.,

Materials and methods

Test guideline
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.

Test material

Constituent 1
Chemical structure
Reference substance name:
Ethylene
EC Number:
200-815-3
EC Name:
Ethylene
Cas Number:
74-85-1
Molecular formula:
C2H4
IUPAC Name:
ethylene

Test organisms

Test organisms (species):
activated sludge

Results and discussion

Effect concentrations
Key result
Duration:
72 h
Dose descriptor:
other: EL50
Effect conc.:
1 760.893 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth inhibition

Applicant's summary and conclusion

Conclusions:
The estimated 72-hr EL50 value for activated sludge is 1760.893 mg/L.
Executive summary:

The aquatic toxicity of this substance was estimated using the Target Lipid Model based on methodologies described by Mcgrath et al. (2004). The estimated 72-hr EL50 value for activated sludge is 1760.893 mg/L.

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