4,4'-sulfonylbisphenol, polymer with ammonium chloride(NH4Cl), pentachlorophosphorane and phenol

Bioaccumulation: aquatic / sediment

Description of key information

No reliable BCF can be determined from this study, because the test concentrations of the three components that were analysed were above the maximum water solubility limit of (any component of) the test substance. The report does not contain any information of the concentration of the truly dissolved test substance and no substance was detected in fish.

An expert evaluation of the BCF was performed and used as supporting evidence for the determination of the potentional B/vB for the PBT assessment.

Additional information

A bioconcentration study for SPS-100 was performed in common carp (Cyprinus carpio) based on a method similar to OECD 305 and according to GLP principles. Following a 56 day (8 weeks) uptake period, steady state bioconcentration factor (BCF) was determined. A depuration phase was not performed since the determined BCFs were low.The study was performed at nominal concentrations of 100 and 1000 µg/L that were achieved via dispersion with emulsifier HCO-40. During the exposure phase, samples from the test solutions were analysed by HPLC, with quantification of the concentration of Peak no. 1. From the report it is not clear which component is indicated by peak 1. The water solubility of SPS-100 was determined based on the analysis of three components: the water solubility of these components were concluded to be <4 µg/L, <28 µg/L and <44 µg/L, respectively (point 4.8 in the IUCLID file). In the bioconcentration study, the measured concentrations of peak 1 in the test solutions were 94-96 µg/L and 960-1030 µg/L for the low and high level, respectively. These concentrations were therefore much higher than the water solubility of (any component of) the test substance. The report does not contain any information of the concentration of truly dissolved test substance. In fish, the concentration of peak 1 was always <2 µg/g, irrespective of the nominal concentration. Furthermore relevant details on test conditions (e.g. photoperiod, mortality in control and treated fish) were not reported and the documentation of the analytical method and results is poor. Therefore the study is considered to be irreliable.In a worst-case approach, it may be assumed that the actual concentration of peak 1 in the test solutions was <4 µg/L. In line with the OECD guidance document on difficult test substances, the concentration in the test solution is taken to be half the LOD (of 4 µg/L), i.e. 2 µg/L. This leads to a provisional BCF value of <2 [µg/g] / 2 [µg/L] = <1 L/g or <1000 L/kg.The current-day OECD 305 guideline for a bioconcentration test in fish indicates that for substances with very low solubility in the aquatic environment, exposure via water may be of limited importance in comparison to the dietary route. This is also indicated by ECHA in IR/CSR Guidance Chapter R.11. Thus, for SPS-100, the bioconcentration study is of limited value.