Reaction product of 9-Octadecenoic acid, (Z)-, sulfonated, potassium salts, hydrogen peroxide and sulfuric acid

Endpoint summary

Additional information

Hydrolysis:

Hydrolysis was determined in accordance to OECD Guideline 111. Standard tests for hydrolysis are not typically appropriate for the test item since PSOA is present as a complex reaction product of unknown and variable composition. However, the end-point assay of the hydrolysis test employed a spectrophotometric method for analysis of peroxycarboxylic acids. This endpoint is characterized for representative hydrocarbon structures that comprise the hydrocarbon blocks used to assess the environmental risk of this substance. The hydrolysis of PSOA was assessed in aqueous buffers at pH 4, 7 and 9 at 50 ± 0.5 °C. After 5 days PSOA was shown to have hydrolysed by considerably greater than 10% at each pH (equivalent to t0.5_25°C<1 year). This indicated that PSOA was hydrolytically unstable and significant hydrolysis had occurred at environmentally relevant pH.

Biodegradation:

PSOA was tested for ready biodegradability in the CO2 Evolution Test according to EU method C.4-C/OECD guideline 301 B. The test item can be considered as rapidly biodegradable but "not readily biodegradable". The degree of biodegradation reached 56% after 28 days. The 10d-window began on day 10, at its end,40 % were reached, staying below the pass level of 60 % given in the OECD guideline.

Transport and Distribution:

The Adsorption Coefficient of PSOA was determined in accordance to OECD Guideline 121. Since PSOA is present as a complex reaction product of unknown and variable composition a range of adsorption coefficient values were determined. The mean adsorption coefficient range of duplicate determinations of the test item was determined as follows:

Log10 Koc of PSOA = Un-retained to 5.28; Koc of PSOA = 0 to 190546