Benzenesulfonic acid, C14-24-alkyl derivatives, magnesium salts, overbased

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Based on read across from structural analogs, the TS (target substance) is expected to show some biodegradation, but not be readily biodegradable. It is also expected that under environmental pH, TS may break down into constituent straight-chain acids, some of which are known to be biodegradable. (Ref: HPV Chemical Challenge Program: Final Revised Test Plan and Assessment with Robust Study Summaries for Linear & Branched Alkylbenzene Sulfonic Acids & Derivatives, Part II: Robust Study Summaries for LAS/ABS Category, prepared by The Soap & Detergent Association LAS/ABS Consortium to U.S. EPA, April, 2008.)

The TS is not expected to be bioaccumulative, based on read across to structural analog and (Q)SAR modeling using Catalogic software from Laboratory of Mathematical Chemistry, Bourgas, Bulgaria (developers of the OECD (Q)SAR Toolbox). The assessment of B was conducted using the worst-case scenario, i.e. using the smallest chain length (R = 14) which is expected to yield the maximum value of BCF. The mmodeling showed that based on the mitigating factor of acids, metabolism and molecular size, the BCF values of all constituents was estimated as < 1000, i.e. not bioaccumulative. The predicted results for bioconcentration could be considered as reliable given that significant portion of representative constituents fall 75% and higher in the model applicability domain. The estimation results and the QMRF for the model are attached within the (Q)SAR record for the Bioaccumulation endpoint.

Structural analogues of the TS does not show any toxicity to both saltwater and freshwater aquatic organisms in acute testing (acute LL/EL 50 > 1000 mg/L in freshwater species and > 10000 mg/L in marine species). There are no data on chronic effects on the TS itself, but based on analog data (CASRN 68411 -30 -3), the long-term NOEC > 0.01 mg/L for both vertebrate and invertebrate species tested (Ref: HPV Chemical Challenge Program: Final Revised Test Plan & Assessment with Robust Study Summaries for Linear & Branched Alkylbenzene Sulfonic Acids & Derivatives, Part II: Robust Study Summaries for LAS/ABS Category., prepared & submitted by The Soap & Detergent Association (SDA) LAS/ABS Consortium, to U.S. EPA, April, 2008.

It is also not classified as a carcinogen, mutagen or reproductive toxicant, according to CLP regulation. There is no other evidence of chronic toxicity, as identified by the substance meeting the criteria for specific target organ toxicity after repeated exposure (STOT RE category 1 or 2), according to CLP regulation.