Registration Dossier

Classification & Labelling & PBT assessment

PBT assessment

Currently viewing:

Administrative data

PBT assessment: overall result

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

Classification of Geranyl isobutyrate for effects in the environment:

 

The chemical Geranyl isobutyrate (CAS no. 2345-26-8) are used as a flavour and fragrance agent. The aim was to assess whether the PBT criterion within Annex XIII was fulfilled for Geranyl isobutyrate. The PBT criterion was herein assessed based on experimental data in conjunction with standardized environmental fate models. Here follows a description of the PBT assessment.

 

 

Persistence assessment

The tested substance does not fulfil the P criterion within Annex XIII based on the assessment that here follows:

 

Biotic degradation

In a prediction done by SSS (2017) using OECD QSAR toolbox version 3.3 with log Kow as the primary descriptor, percentage biodegradability of test chemical3,7-dimethylocta-2,6-dien-1-yl 2-methylpropanoate(CAS No. 2345-26-8) was estimated. Test substance undergoes 90.5% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical 3,7-dimethylocta-2,6-dien-1-yl 2-methylpropanoate was estimated to be readily biodegradable in water.

 

In another prediction using the Estimation Programs Interface Suite (EPI suite, 2017), the biodegradation potential of the test compound 3,7-dimethylocta-2,6-dien-1-yl 2-methylpropanoate(CAS No. 2345-26-8) in the presence of mixed populations of environmental microorganisms was estimated. The biodegradability of the substance was calculated using seven different models such as Linear Model, Non-Linear Model, Ultimate Biodegradation Timeframe, Primary Biodegradation Timeframe, MITI Linear Model, MITI Non-Linear Model and Anaerobic Model (called as Biowin 1-7, respectively) of the BIOWIN v4.10 software. The results indicate that chemical 3,7-dimethylocta-2,6-dien-1-yl 2-methylpropanoate is expected to be readily biodegradable.

 

The experimental data for read-across substances (CAS: 24851-98-7 and 131-17-9) also indicate that they are readily biodegradable.

 

Environmental fate

According to the fugacity model levels III, the most likely environmental fate for this test chemical is soil (i.e.estimated to 81%). In soil, Geranyl isobutyrate was expected to have negligible to slow mobility based upon an estimated Log KOC in the range 3.1 – 3.9. The half-life in soil (30 days estimated by EPI suite) indicates that the chemical is not persistent in soil and the exposure risk to soil dwelling animals is moderate to low.

 

If released in to the environment, 18 % of the chemical will partition into water according to the Mackay fugacity model level III in EPI suite version 4.1 (2016). However, the half-life (15 days estimated by EPI suite) indicates that the exposure risk to aquatic animals is moderate to low.

 

Moreover, its persistent characteristic is only observed in the sediment compartment but Fugacity modelling shows that sediment is not an important environmental fate (less than 1% when estimated by EPI Suite version 4.1).

 

Hence it has been concluded that Geranyl isobutyrate is not persistent in nature.  

 

 

Bioaccumulation assessment

The tested substance does not fulfil the B criterion within Annex XIII based on the assessment that here follows:

 

The estimated BCF value for the substance is in the range 1485 - 1700 L/kg wet wt. If this chemical is released into the aquatic environment, there should be a low risk for the chemical to bioaccumulate in fish and food chains.

 

Toxicity assessment

The tested substance does not fulfil the T criterion within Annex XIII based on the assessment that here follows:

 

Mammals

The tested chemical is regarded to be not classified for carcinogenicity, mutagenicity and reprotoxicity, Further, there is no evidence of chronic toxicity, as identified by the classifications STOT (repeated exposure), category 1(oral, dermal, inhalation of gases/vapours, inhalation of dust/mist/fume) or category 2 (oral, dermal, inhalation of gases/vapours, inhalation of dust/mist/fume).

 

Aquatic organisms

 

All of the available short-term eco-toxicity estimation for invertebrates and algae for the substance indicates the LC50/EC50 value to be in the range 48 – 50 mg/L. These value suggest classification in Aquatic chronic 3 category but since the substance is readily biodegradable in nature, hence it was considered to be not classified as per the CLP regulation.

 

There are no available long-term toxicity evaluations for Geranyl isobutyrate. By speculation, long-term NOEC for aquatic organisms were not expected for the substance at concentration below 0.01 mg/L based on the data mentioned above.

 

The chemical was therefore not considered as hazardous to aquatic environments as per the criteria set out in Annex XIII.

 

Conclusion

Based on critical, independent and collective evaluation of information summarized herein, the tested compound does not fulfil the P, B and T criterion and has therefore not been classified as a PBT compound within Annex XIII.