Benzenesulfonic acid, 4-(1-methylethyl)-, potassium salt (1:1)

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Persistence: As defined in the ‘Read-Across Justification Document’ section 13, data provided for the hydrotropes category are representative of potassium p-cumene sulphonate and suitable for assessment purposes. A GLP guideline study using sodium toluene sulphonate (CAS 657-84-1) reported almost complete biodegradation by the end of the 28-day test of 99.8% and met the 10-day window criterion with more than 60% degradation recorded after 7 days (Brunswick-Titze, 2004). Evidence of ready biodegradability from studies for hydrotrope category substances tested using OECD guideline methods supports the conclusion that potassium p-cumene sulphonate is readily biodegradable. In addition, the OECD SIDS Report (2006) for the hydrotropes category concluded that “studies across the hydrotropes category demonstrate rapid and complete biodegradation under aerobic conditions and the hydrotropes are considered to be readily biodegradable according to OECD criteria”. The OECD SIDS Report conclusion supports the experimental evidence provided and the substance is considered to be not persistent. According to ECHA Guidance on PBT assessment, no further testing is required to conclude the P criterion.

Bioaccumulation: The likelihood of bioaccumulation is considered to be very low based on the evidence from a measured partition coefficient for potassium p-cumenesulphonate (log Kow of -1.4) and scientific evidence in the published literature. Reliable experimental studies carried out in accordance with OECD Guideline 305C determined bioconcentration factors of <2.3 for two hydrotrope category substances published in the OECD SIDS Report for hydrotope category substances (2006). Potassium p-cumenesulphonate does not fulfil the criteria “bioaccumulative (B)” or “very bioaccumulative (vB)”. According to ECHA Guidance on information requirements and chemical safety assessment (November 2012), Chapter R.11, Figure 11-2: Integrated testing strategy for B-assessment, no further testing is required to conclude the bioaccumulation criterion.

Toxicity: Available reliable data for the long-term aquatic toxicity of hydrotrope category substances shows the NOEC is greater than 0.01 mg/L and the substances does not fulfill the criterion for toxicity according to ECHA guidance on PBT assessment. Additionally, short-term acute toxicity (LC₅₀or EC₅₀) to aquatic organisms is greater than 0.01 mg/L and does not meet the screening toxicity criterion according to the ECHA guidance on PBT assessment (Part C). There is no evidence of chronic toxicity considering human health and no classification as carcinogenic (category 1 or 2), mutagenic (category 1or 2) or toxic for reproduction (category 1, 2, or 3) according to Directive 67/548/ECC.   Therefore, it can be concluded that the substance does not fulfill the toxicity (T) criterion as laid down in Annex XIII of regulation (EC) No 1907/2006 (amended March 2011 as No 253/2011).

The overall conclusion is that potassium p-cumenesulphonate does not meet the PBT or vPvB criteria. No further testing is required.