Benzenesulfonic acid, C10-60-alkyl derivs., barium salts

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

The substance displays properties that indicate persistency within the environment, based on low ready biodegradability. Due to the inorganic elements in the chemical structure, the substance can never readily biodegrade. Furthermore, due to the extremely low water solubility, the hydrolysis of the substance cannot be measured although the chemical structure would suggest that hydrolysis is unlikely to occur.

As such, the substance fulfils the requirements of Annex XIII, Para 1.1 based on evaluation of available data, and can be considered to be “P” based in this data.

The weight of evidence presented below based on read across to calcium sulfonates demonstrates that CLP/GHS classification as hazardous to the aquatic environment is not justifiable and that the hazard profile does Not meet the B or vB criteria. This assessment should apply to all barium and calcium sulfonates whether natural or synthetic, whether high or low TBN and may also apply to other sulfonates (e.g., Mg, Na) based on further evaluation.

Calcium sulfonate: logKow >6.65^a

Sodium sulfonate: logKow 10.88

Calcium sulfonate: logKow (QSAR) 17.9

Calcium sulfonates: logKow >6.7

Calcium sulfonate: logKow >4.46

Calcium sulfonate: logKow >5.47

Calcium sulfonate: logKow (QSAR):

Log Pow 18.05 @ 25C for CAS# 70024-69-0

Log Pow 25.44 @ 25C for CAS# 61789-85-3

Log Pow 31.87 @ 25C for CAS# 61789-86-4

Log Pow 14.66 @ 25C for CAS# 68584-22-5

Log Pow 16.09 @ 25C for CAS# 68584-23-6

Log Pow 16.61 @ 25C for CAS# 68608-26-4

Log Pow 10.68 @ 25C for CAS# 70024-67-8

Log Pow 41.63 @ 25C for CAS# 90194-27-7

Log Pow 24.06 @ 25C for CAS# 97675-24-6

Log Pow 35.05 @ 25C for CAS 617-87-5

Log Pow 15.43 @ 25C for CAS 68584-26-9

Log Pow 41.08 @ 25C for CAS 61790-48-5

Calcium sulfonate: BCF prediction(QSAR)BCF in fish less than 100 L/kg, BCF in fish of 11 L/kg

CAS 61789 -87 -5: BCF prediction (QSAR) BCF in fish 1.85 L/kg

Calcium sulfonate: Read Across to similar structures with experimental BCF; Japan CHRIP database presents 3 similar substances (CAS#81-11-8; 88-44-8; 121-03-9) with experimental BCF values in carp of <5CAESAR model found two similar structures (ID 113 and 302) with experimental BCF values in fish which were less than 20 L/kg

Various sulfonates: Molecular weight; Molecular weight of surfactant portions is often >1,000 which results in low potential for bioavailability and bioaccumulation

Various sulfonates: Water solubility; Water solubility is very low, measured values typically less than 0.1 ppm, thereby limiting potential for exposure and accumulation and making it technically not feasible to even run an experimental BCF study even if warranted.

Various sulfonates: Ecotoxicity; Low potential for acute and chronic ecotoxicity, suggesting limited potential for protein absorption, bioavailability, and bioconcentration

Various sulfonates: Molecular diameter; High diameter limits potential for bioaccumulation

Various sulfonates: Component analysis; Sulfonates are often produced and supplied in the presence of significant amounts of mineral oil (e.g., >40%) which is of low bioaccumulation potential and thereby limits the B potential of the overall substance

^aExperimental testing for water solubility and octanol-water partition coefficient for the calcium sulfonates is considered extremely challenging following OECD guidelines because the sulfonate components can dissociate from the calcium atom an form a suspension with surfactant properties, which is why greater than values were used for logKow. The language in the Harlan report states that because the water solubility was so low, resulting in less than values for water solubility, it resulted in a partition coefficient estimate with a greater than value, and that the actual logKow would be greater than that value of >6.65 presented.

As such, the substance is considered not to fulfil the requirement of Annex XIII, Para 1.2 based on evaluation of available data, and cannot be considered to be “B” or “vB” based on the available data.

The LC50 in freshwater fish is considered to be >1000mg/l and >10000 mg/l with marine species. The substance is, therefore, considered not toxic to freshwater or marine fish species. Nevertheless, adequate controls will be in place during production and use to ensure that the substance is not released to the environment.

The EC50 in freshwater Daphnia is considered to be >1000mg/l. The substance is, therefore, considered not toxic to Daphnia magna. Nevertheless, adequate controls will be in place during production and use to ensure that the substance is not released to the environment.

The toxicity of the substance has not been assessed using marine invertebrate species, but it is considered likely to be similar to freshwater species.

The EC50 in freshwater algae is considered to be >1000mg/l. Two of the studies available support this conclusion, while the one remaining study did not exceed 100 mg/l, although the data support the conclusion that the EC50 is above this dose level. As this dose level has been included in the other studies conducted, it is considered acceptable to consider this as supporting data but to conclude that the highest dose level attained from studies considered reliable is both appropriate and adequately supported by the data.

All of the data available for the registered substance to assess the mutagenic, clastogenic and genotoxic effects of the substance in vitro and in vivo. All the studies achieved negative results.

Data have been included that were conducted on sodium and magnesium salts. The sodium and magnesium ions are considered likely to be more active than calcium and the data is therefore considered suitable as supporting data for the endpoint.

Based on the in vitro and in vivo data available for the substance, the substance is considered to be not genotoxic.

The data from one study is available. No effects were observed at the maximum dose concentration assessed. The NOAEL = 500mg.kg.day.

On the basis of other data it is considered unjustifiable to conduct any carcinogenicity data assessment, but the substance is considered non carcinogenic on the basis of the data available.

Data from two 28-day oral toxicity studies are available with exposure by oral gavage to linear and branched alkaryl benzene sulphonates upto a maximum dose of 1000 mg/ml/day. Relatively slight effects were observed in either study, limited to a reduction in cholesterol in serum at high dose animals only in one study. The lowest dose at which no adverse effects were observed effects were observed is, therefore, taken as the appropriate effect level. NOAEL=500mg/kg/day

The data from only one 28-day toxicity test by the inhalation route is available. The test substance is, however, extremely difficult to test by this route and, due to the nature of the substance in mineral oil, any effects due to the test sample are masked by the effects of the mineral oil. The NOAEC is, therefore, determined by extrapolation to oral exposure. NOAEC = 881.58 mg/m3

The data from two 28-day dermal toxicity studies are available to assess dermal toxicity by repeated dose. No systemic toxicity was observed in either study. NOEL = 1000 mg/kg/day .

As such, the substance does not to fulfil the requirement of Annex XIII, Para 1.3 based on evaluation of available data, and cannot be considered to be “T” based on the available data.

Likely routes of exposure:

The neat substance would be manufactured and formulated products containing the substance would be produced in closed systems. Furthermore, the substance can never be isolated from a mineral oil solvent that is essential to maintain the structural equilibrium of the substance. Removal of this solvent would degrade the chemical structure from the structure of the registered substance.

By QSAR analysis, the substance is anticipated to be a solid with an extremely low vapour pressure. Furthermore, its physical state in the solvent is a highly viscous liquid. The substance is not, therefore, expected to be readily available to the air at ambient conditions.

Nevertheless, recommendations for handling and disposal would be made that are intended to avoid exposure of the substance to the various compartments of the environment during the whole lifecycle of the substance. Controls recommended on the product lifecycle are specifically intended to avoid emission of the substance to air. The neat substance would be manufactured and formulated products containing the substance would be produced in closed systems. Furthermore, the substance can never be isolated from a mineral oil solvent that is essential to maintain the structural equilibrium of the substance. Removal of this solvent would degrade the chemical structure from the structure of the registered substance.

By QSAR analysis, the substance is anticipated to be a solid with an extremely low vapour pressure. Furthermore, its physical state in the solvent is a highly viscous liquid. The substance is not, therefore, expected to be readily available to the air at ambient conditions.

Nevertheless, recommendations for handling and disposal would be made that are intended to avoid exposure of the substance to the various compartments of the environment during the whole lifecycle of the substance. Controls recommended on the product lifecycle are specifically intended to avoid emission of the substance to air.