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Classification & Labelling & PBT assessment

PBT assessment

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PBT assessment: overall result

PBT status:
the substance is not PBT / vPvB
Justification:

P criteria

The substance is not readily biodegradable according to both the estimated value with EPYSUITE 4.1 and the read across with the available data for the substance 16470-24-9 that achieves 1,2% in 28 days.

 

According to the hydrolysis available data for the substance 16090 -02 -1 (read across), the substance 133-66-4 can be considered stable in the environment at a pH between 4 and 9 for more than 1 year.

Therefore it is assumed that the substance CAS 133-66-4 is stable in water as well.

The substance is then considered to be persistent in the environment were exposure to occur based on the known lack of biodegradability.

 

B criteria

The bioconcentration factor (BCF) has been calculated as 10 L/kg wet-wt. using QSAR estimation based upon the SMILES code of the molecular structure Arnot-Gobas BCF & BAF Methods by structural fragmentation of the EPI Suite v4.1.

 

The bioaccumulation potential was also tested with a close structural analogue (read across with 16090-02-1) on fish, and after 70 days of exposition to the substance no detectable or very close to the method sensitivity threshold bioconcentration values were found.

 

The partition coefficient of the substance has been calculated using QSAR estimation based upon the SMILES code of the molecular structure US EPA KOWWIN v1.68 of the EPI Suite v4.1. Based upon structural fragmentation drawn from a database of >40,000 substance, the log Pow is estimated to be 8.96. High log Pow is likely to be due in part to the hydrophobic nature of the molecule.

 

Furthermore, assessment of the Toxicokinetic activity of the substance 16090-02-1 (read across) conducted with a radioisotope demonstrates that a rapid and complete excretion of radioactive material was observed: more than 95% of the administered radioactive material was excreted by faeces within 48 hrs.

 

Based on these data the substance is considered to be non-bioaccumulating.

 

T criteria

Eco-toxicity studies:

The toxicological examination on a close structural analogue (read across with 16090-02-1) on fish, daphnia and algae provided an EC50 >100 mg/L.

 

The toxicological examination of the chronic toxicity to aquatic invertebrates on a close structural analogue (read across with 16090-02-1) provided a NOEC= 1 mg/L.

 

Mammalian toxicity studies:

Also in this case the toxicological examination on a close structural analogue (read across with 16090-02-1) for genetic toxicity demonstrated a lack of mutagenic response.

Mutagenicity in bacterial reverse mutation assays (Ames test) investigated on a close structural analogue (read across with 16090-02-1), provided negative results with and without metabolic activation.

Also the induction of micronuclei in vivo investigated on mice, which were orally treated with a close structural analogue (read across with 16090-02-1), at doses of 5000 mg/kg/bw, provided no increase in the number of micronuclei. No toxic effects were observed

The Prenatal Developmental Toxicity, on a close structural analogue (read across with 16470-24-9), produced a NOAEL =1000 mg/kg bw/day.

 

Considering all the available toxicological information the substance can be assessed as not toxic.

 

The substance may pose a persistence (P) hazard but as the results produced no bioaccumulation (B) or toxicity (T) properties the substance cannot be considered as a PBT/vPvBT.

Since the criteria for B and T are not fulfilled, the substance is not PBT or vPvB