2-(4-fluorophenyl)-5-(5-iodo-2-methylbenzyl)thiophene

PBT assessment

PBT assessment: overall result

Reference

Name:

T003063

Type of composition:

legal entity composition of the substance

State / form:

solid: particulate/powder

Related composition:

T003063

Reference substance:

T003063

PBT status:

the substance is PBT / vPvB

Justification:

An evaluation of the inherent properties of T003063 is performed against the ANNEX XIII criteria. If insufficient data were available, the screening criteria as laid down in ECHA Guidance on information requirements and chemical safety assessment Chapter R.11: PBT Assessment (2014) were applied.

The persistency assessment is based on the screening criteria in Annex XIII of the REACH Regulation. The biodegradation potential of the test substance, T003063 has been assessed in a reliable (Klimisch 1) guideline (OECD 301B) study (Desmares-Koopmans, 2016), within which the substance was considered to be not readily biodegradable under the conditions of the test. Since, the water solubility of the test item is 6.70 µg/L which is more than the maximum concentration to be used in the hydrolysis study (3.35 µg/L), a hydrolysis study could not be performed. Due to these results on degradation, it cannot be ruled out completely that the substance is potentially P or even vP.

The bioaccumulation assessment is based on the screening criteria in Annex XIII of the REACH Regulation. In a guideline (OECD 117) study (Brekelmans, 2016) the measured log Kow was > 7.2. Octanol-water partitioning has become a common method for evaluating the potential of a substance to bioaccumulate; however, a major disadvantage of octanol-water partitioning is that experimental determination can be subject to very large measurement errors. For hydrophobic substances such as T003063, the screening log Kow value of > 7.2 should be treated with care. Several specific cut-off values in terms of log Kow are proposed (van Wijk et al, 2009; Gobas et al, 2009) and the current REACh guidance applies the cut-off criterion of log Kow of less than 4.5 because of lack of affinity for lipids of aquatic organisms (ECHA, 2008a).

For highly hydrophobic chemicals, the bioaccumulation potential in aquatic organisms tends to decrease with increasing log Kow. Chemicals with log Kow > 6 to 7 showed decrease of uptake efficiency to mammalian organisms (Kelly et al, 2004). For fish, a log Kow of > 10 is applied as one of the indicators for not being B/vB in REACh Guidance R.11.

In the absence of any further data relevant to the determination of bioaccumulation it must be considered that T003063 meets the criteria for classification as B and vB.

The toxicity assessment is based on the screening criteria in Annex XIII of the REACH Regulation. Taking into account the available data and the criteria of the CLP regulation (REGULATION (EC) N° 1272/2008), the substance does not fulfill the screening criterium for being considered as T.

The assessment of PBT / vPvB properties is based upon a separate assessment for each parameter (i.e. P or vP, B or vB and T). Substances are only assigned as PBT or vPvB when they fulfil the criteria for all three properties (persistency, bioaccumulation and toxicity in case of PBT substance) or both criteria (i.e. very persistent and very bioaccumulative) in case of vPvB, respectively.

The substance is not T, hence, it does not have to be regarded as PBT. However, the screening criteria for both vP and vB are met, so the substance must be regarded as vPvB. Due to the limited amount of data, this is considered to be a worst case classification. However, further P and B evaluation of this substance is at this stage not considered warranted because of its current production and use within the EU, which indicates only very limited environmental release.