Reaction mass of 4-(2,6,6-trimethylcyclohex-2-ene-1-yl)-but-3-ene-2-one and 4-(2,6,6-trimethylcyclohex-1-ene-1-yl)-but-3-ene-2-one

PBT assessment

PBT assessment: overall result

Reference

Name:

Reaction mass of (E)-4-(2,6,6-trimethylcyclohex-2-ene-1-yl) -but-3-ene-2-one and (E)-4-(2,6,6-trimethyl-1-cyclohexen-1-yl)-3-buten-2-one

Type of composition:

boundary composition of the substance

State / form:

liquid

Reference substance:

Reaction mass of (E)-4-(2,6,6-trimethylcyclohex-2-ene-1-yl) -but-3-ene-2-one and (E)-4-(2,6,6-trimethyl-1-cyclohexen-1-yl)-3-buten-2-one

Reference substance:

Reaction mass of (E)-4-(2,6,6-trimethylcyclohex-2-ene-1-yl) -but-3-ene-2-one and (E)-4-(2,6,6-trimethyl-1-cyclohexen-1-yl)-3-buten-2-one

PBT status:

the substance is not PBT / vPvB

Justification:

Classification of Reaction mass of 4-(2,6,6-trimethylcyclohex-1-ene-1-yl)-but-3-ene-2-one and 4-(2,6,6-trimethylcyclohex-2-ene-1-yl)-but-3-ene-2-one for effects in the environment:

 

The chemical Reaction mass of 4-(2,6,6-trimethylcyclohex-1-ene-1-yl)-but-3-ene-2-one and 4-(2,6,6-trimethylcyclohex-2-ene-1-yl)-but-3-ene-2-oneis used as a flavouring and fragrance agent.The aim was to assess whether the PBT criterion within Annex XIII was fulfilled for Reaction mass of 4-(2,6,6-trimethylcyclohex-1-ene-1-yl)-but-3-ene-2-one and 4-(2,6,6-trimethylcyclohex-2-ene-1-yl)-but-3-ene-2-one.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

On the basisof the variousexperimental biodegradation studies from reliable sources of test chemicalReaction mass of 4-(2,6,6-trimethylcyclohex-1-ene-1-yl)-but-3-ene-2-one and 4-(2,6,6-trimethylcyclohex-2-ene-1-yl)-but-3-ene-2-oneperformed as per the OECD TG / other suitable test guidelines; percentage degradation of test chemical was evaluated to be 60% & 71% using oxygen consumption parameter after 28 days further fulfilling the validity criterion of the test and thus,chemical was considered to be readily biodegradable in water.

 

Experimental results from the read across substance also indicate that they are readily biodegradable.

 

Thus, based on the available information, it indicates thatchemicalReaction mass of 4-(2,6,6-trimethylcyclohex-1-ene-1-yl)-but-3-ene-2-one and 4-(2,6,6-trimethylcyclohex-2-ene-1-yl)-but-3-ene-2-oneis considered to be readily biodegradable in water and hence, likely to be not persistent (not 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 be158.7 L/kg and the octanol water partition coefficient of the test chemical was determined to be 4.0 at 24°C as per the OECD TG 117and 3.802± 0.001 at 25°C as per OECD TG 107, respectively, which is less than 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 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 data as per OECD TG / EU methods for fish, algae and aquatic invertebrate for the substanceReaction mass of 4-(2,6,6-trimethylcyclohex-1-ene-1-yl)-but-3-ene-2-one and 4-(2,6,6-trimethylcyclohex-2-ene-1-yl)-but-3-ene-2-oneindicates the LC50/EC50 value to be in the range > 5 to 50.26 mg/L, respectively. These value suggest that the substance is likely to be hazardous to aquatic organisms at environmentally relevant concentrations. Since the test chemical is readily biodegradable in nature, chemical was considered as non-toxic to aquatic organisms and hence, considered to be ‘not classified’ as per the CLP regulation.

 

On the basis ofthe various experimental study oflong term eco-toxicity data for aquatic invertebratesas per OECD TG 211of the substanceReaction mass of 4-(2,6,6-trimethylcyclohex-1-ene-1-yl)-but-3-ene-2-one and 4-(2,6,6-trimethylcyclohex-2-ene-1-yl)-but-3-ene-2-one; the 21 d NOEC was determined to be 0.175 mg/l, respectively. These value suggest that the substance is likely to be hazardous to aquatic organisms at environmentally relevant concentrations and hence, considered to be classified in ‘Aquatic chronic category 3’ 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 does not fulfil the P, B and T criterion and has therefore not been classified as a PBT compound within Annex XIII.