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

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

weight of evidence

Justification for type of information:

The short-term toxicity to aquatic invertebrates can be predicted by read across to the alkyl benzene derivitatives 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 aquatic invertebrates 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 is used as a boundary value. The read across justification document is attached in IUCLID section 13.

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

2.4 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Conclusions:

No chronic 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 48-h LC50 of the target substance can be considered 2.4 mg/L, based on read across to the group alkyl benzene derivatives (worst case approach).

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

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 chemcials to aquatic organisms using the ECOSAR class program

Remarks on result:

other: QSAR result: 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 daphnia

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 daphnia.
Based on this, the substance is not expected to demonstrate acute aquatic toxicity at water soluble concentrations.

Conclusions:

According to data from a substance in the category and QSAR modelling of HiMo LABS, the substance does not demonstrate short-term toxicity to aquatic invertebrates.

Description of key information

No data on acute toxicity to aquatic invertebrates is available for HiMO LABS.  Structural analogues (alkylbenzene derivatives) were used to understand the acute toxicity profile of substance to daphnia. A study from LABS Na (CAS no: 68411-30-3) was used to cover this endpoint. Using a conservative approach, the 48-hr EC50 was set to 2.4 mg a.i/L. HiMO LABS however has a very low water solubility demonstrated by QSAR modelling. .According to data from a category substance and QSAR modelling of HiMo LABS, indicating an extremely low water solubility, the substance does not demonstrate acute aquatic toxicity to daphnia at water soluble concentrations.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

2.4 mg/L