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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Degradation :

Both DSP and TSP are found to be hydrolytically stables.

Screening readily biodegradation test do not show a significant degradation potential for DSP nor TSP.

QSARs calculations were performed on TSP to predict potential degradation pathway of the compound.

A soil simulation test was conducted according to OECD 307 guideline. The average half life for the four soils of 7.3 days (from 3.13 to 12.5 days) demonstrates that TSP is not expected to be persistent in the environment.

Bioaccumulation:

A fish bioaccumulation dietary test was conducted according to OECD 305 guideline with a mixture of TSP/DSP. This study demonstrated that DSP had no potential for bioaccumulation. For TSP a BMF lipid normalized result of 0.355 was obtained indicating no potential for biomagnification. The authorities concluded nevertheless that TSP had to be considered as potentially very bioaccumulative on the basis of extrapolated values from the uptake and depuration phases.

Additional information

Due to the differences in the physicochemical characteristics of the components of the reaction mass of 2,4,6 -tris(1 -phenylethyl)phenol and Bis(1 -phenylethyl)phenol, any distyrenated phenol and tristyrenated phenol released to the environment will not behave as a single compound. Significant variation is expected in the environmental fate and behaviour of these compounds. As a consequence, it was considered more appropriate to conduct this assessment for each component, that is to say for Tristyrenated phenol (TSP) and Distyrenated phenol (DSP).

One reliable key study on the hydrolysis potential of DSP is available (Lange, 2006). DSP was found to be hydrotically stable in the four test conditions: buffer solution at pH 7 saturated with nitrogen, algal test medium (according to OECD TG 201) saturated with nitrogen, buffer solution at pH 7 saturated with oxygen and algal test medium (according to OECD TG 201) saturated with oxygen. As TSP contains the same functional groups as DSP, TSP is not expected to have a higher hydrolysis potential than DSP. Moreover, this assumption is supported by the steric hindrance caused by the additional styrene group substituted on the phenol ring of TSP. Therefore, it is considered that TSP is hydrotically stable in similar conditions as DSP.

One reliable key study (BAZZON, 1997) is available for the assessment of the ready biodegradability.The test substance (80% TSP and 20% DSP) was found to be not readily biodegradable with pre-adapted inoculum. As no biodegradation was observed during the test, it is proposed to apply this conclusion to both components DSP and TSP.

This was further confirmedd by way of the Catalogic QSAR. The model prediction indicates that the individual constituents TSP, 2,6-DSP and 2,4-DSP are not ready biodegradable.

The Catalog model does predict a number of soil degradation pathways for TSP, 2,6-DSP and 2,4-DSP. The predicted biodegradation in soil is supported by documented metabolism for an analogue chemical. The model however does not provide a soil degradation half-life.

A soil simulation test conducted according to OECD 307 guideline with radiolabelled TSP demonstrated that neither TSP, nor its major metabolites would be considered as persistent. The average half life for TSP is calculated to be 7.3 days for four soils (from 3.13 to 12.5 days) at 12°C. The test was also conducted at 20°C where slightly faster degradation was observed for some of the soils.

Based on the measured logKow values above 6, DSP and TSP may have a potential of bioaccumulation. One reliable key dietary bioaccumulation study (Lange, 2006) is available on a mixture of TSP / DSP (60% / 40%). This study showed that DSP is not bioaccumulable. For TSP, the study determined a lipid-normalized BMF of 0.355, therefore, it has a low potential for biomagnification. However, using the ratios of the uptake and depuration rates, a BCF value > 10000 was extrapolated, the UK Env Agency concluded there was a potential for TSP to be very bioaccumulable.