3-(5,5,6-trimethylbicyclo[2.2.1]hept-2-yl)cyclohexan-1-ol

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Classification of 3 -(5,5,6-trimethylbicyclo[2.2.1]hept-2-yl)cyclohexan-1-olfor effects in the environment:

 

The chemical 3-(5,5,6-trimethylbicyclo[2.2.1]hept-2-yl)cyclohexan-1-ol(CAS no. 3407-42-9) is used as a flavouring agent.The aim was to assess whether the PBT criterion within Annex XIII was fulfilled for3-(5,5,6-trimethylbicyclo[2.2.1]hept-2-yl)cyclohexan-1-ol.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 fulfils the P criterion within Annex XIII based on the assessment that here follows:

 

Biotic degradation

28-days Closed Bottle test following the OECD guideline 301 D was performed to determine the ready biodegradability of the test item. The study was performed at a temperature of 20°C. The test system included control, test item and reference item. Polyseed were used as inoculum with bacterial count as 107 to 108 CFU/ml. The concentration of test and reference item (Sodium Benzoate) chosen for both the study was 4 mg/L, while that of inoculum was 32ml/L. OECD mineral medium was used for the study. ThOD (Theoretical oxygen demand) of test and reference item was determined by calculation. % degradation was calculated using the values of BOD and ThOD for test item and reference item. The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 73.49 %. Degradation of Sodium Benzoate exceeds 39.15 % on 7 days & 61.44 on 14th day. The activity of the inoculum is thus verified and the test can be considered as valid. The BOD28 value of test chemical was observed to be 0.42 mgO2/mg. ThOD was calculated as 3.04 mgO2/mg. Accordingly, the % degradation of the test item after 28 days of incubation at 20 ± 1°C according to Closed Bottle test was determined to be 13.81 %. Based on the results, the test item, under the test conditions, was considered to be not readily biodegradable in nature.

 

AnotherBiodegradation experiment was carried out for determining biodegradability of test chemical in this experiment non adapted activated sludge was used as inoculums at 30 mg/L concentration for 28 days. Biodegradation was analyzed by using two parameters namely O2 consumption and test material analysis by GC. The initial concentration of test chemical was 100 mg/L. After 28 days of incubation Percent biodegradation of test chemical was observed to be 0.0% by by O2 consumption parameter and 3% test material analysis by GC parameter in 28 days. Therefore it is concluded that test chemical is not readily biodegradable.

 

Thus, based on the available information, it indicates thatchemical3-(5,5,6-trimethylbicyclo[2.2.1]hept-2-yl)cyclohexan-1-olcan be considered to be not readily biodegradable in water and thus likely to be persistent (P) 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 from authoritative databases was determined to be 1985L/kg and the octanol water partition coefficient of the test chemical was determined to be 4.64, respectively, which is close to the threshold of 4.5. 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 fulfil the T criterion within Annex XIII based on the assessment that here follows:

 

Mammals

The tested chemical is regarded to be classified for reprotoxicity in Category 2.

The tested chemical is regarded to be not classified for carcinogenicity, mutagenicity,

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).

 

The chemical was therefore considered as hazardous as per the criteria set out in Annex XIII.

  

Aquatic organisms

All of the available short-term eco-toxicity data for invertebrates and algae for the substance3-(5,5,6-trimethylbicyclo[2.2.1]hept-2-yl)cyclohexan-1-olindicates the LC50/EC50 value to be in the range 2.59 mg/l to 39.76 mg/L, respectively and on the basis of the various experimental studies of short term eco-toxicity data for fish of the structurally and functionally similar read across chemical (including the biodegradability of read across chemical) and applying the weight of evidence approach, the EC50 value was determined to be ranges from 17.6 to 18.9 mg/l, respectively. Whereas on the basis of the long term eco-toxicity data for fish, the NOEC value was evaluated to be 0.156 mg/l and for aq. Invertebrates, the EC10 value was determined to be 0.148 mg/l, respectively. These value suggest that the substance is likely to be hazardous to aquatic organisms at environmentally relevant concentrations and can be considered to be classified in ‘Aquatic chronic category 2’ as per the CLP regulation.

 

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 fulfils the P and T criterion, but does not fulfil the B criterion and has therefore not been classified as a PBT compound within Annex XIII.