Benzenesulfonic acid, 4-C20-24 (even numbered) sec-alkyl derivs.

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Justification for type of information:

The short-term toxicity to fish parameter can be predicted by read across to the alkyl benzene derivatives category from which the conclusion can be drawn that an increasing carbon chain length causes a decrease in water solubility. Based on this, it can be expected that the short-term toxicity to fish for benzene sulfonic acid, C20-24 will be very low. Though as a worst case approach, the result of the category member with the highest water solubility value (LABSNa) is used as a boundary value. The read across justification document is attached in IUCLID section 13.

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 1.67 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Remarks on result:

other: The outcome is based on read across to alkylbenzene derivatives (worst case approach)

Details on results:

The result is observed for the highly soluble C10-13-alkyl derivs. sodium salts and thus used as the lower limit.

Conclusions:

No acute fish study with the target substance is available. Data generated with the category substance LABS Na is considered pivotal to this endpoint and this is the most conservative approach. The 96-h LC50 of the target substance can be considered > 1.67 mg/L, based on read across to the group alkyl benzene derivatives (worst case approach).

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a (Q)SAR model, with limited documentation / justification, but validity of model and reliability of prediction considered adequate based on a generally acknowledged source

Justification for type of information:

QSAR prediction

Guideline:

other: REACH Guidance on QSARs R.6

Principles of method if other than guideline:

Mayo-Bean K., Moran-Bruce K., Nabholz J.V., Meylan W.M., Howard, P.H. 2012. Methodology document for the ecological Structure-Activity Relationship Model (ECOSAR) Class Program
Estimating toxicity of industrial chemicals to aquatic organisms using the ECOSAR class program

Key result

Remarks on result:

other: QSAR result: the aquatic acute toxicity value exceeds (i) the predicted water solubility, indicating the substance is not soluble enough to measure the predicted effect and (ii) the log Kow cutoff value of 5.0 for acute toxicity to fish.

Details on results:

The EPISUITE QSAR modelling was used to predict the acute toxicity profile of HiMo LABS. Modelled toxicity values for HiMo LABS (C20 and C24 alkyl derv.) confirmed that the aquatic acute toxicity value exceeds (i) the predicted water solubility, indicating the substance is not soluble enough to measure the predicted effect and (ii) the log Kow cutoff value of 5.0 for acute toxicity to fish. As a result, HiMo LABS is not expected to exhibit acute aquatic toxic effects.

Conclusions:

According to data from a substance in the cateory and based on EPISUITE QSAR modelling, HiMoLABS is not expected to exhibit acute toxicity to fish.

Description of key information

No data on acute toxicity to fish is available for the target substance.  Data from the alkylbenzene derivatives were used to understand the acute toxicity profile of the substance to fish. The toxicity with freshwater fish has been measured experimentally for multiple category members. Based on the worst case approach, the 96-h LC50 value is considered > 1.67 mg a.i./L.  HiMo LABS has a very low water solubility demonstrated with QSAR modelling. Furthermore EPISUITE QSAR modelling was used to predict the acute toxicity profile of HiMo LABS. Modelled toxicity values for HiMo LABS (C20 and C24 alkyl derv.) confirmed that the aquatic acute toxicity value exceeds the predicted water solubility, leading to the conclusion that it doesn't exhibit acute aquatic toxicity. It can be concluded that the target substance does not demonstrate acute aquatic toxicity at water soluble concentrations.