2-benzylideneheptanal

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Classification of 2-benzylideneheptanal for effects in the environment:

 

The chemical 2-benzylideneheptanal (CAS no. 122-40-7) is used as a flavour and fragrance agent. The aim was to assess whether the PBT criterion within Annex XIII was fulfilled for 2-benzylideneheptanal. 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 an experimental key study from peer reviewed journal (A. M. Api et. al, 2015), biodegradation experiment was conducted for 28 days for evaluating the percentage biodegradability of test substance (2E)-2-(phenylmethylidene)heptanal (CAS no. 122-40-7) under aerobic conditions. The study was performed according to OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test). Concentration of inoculum i.e, sludge used was 30 mg/l and initial test substance conc. used in the study was 100 mg/l, respectively. Aniline was used as a reference substance for the study. Test vessel involve the Bottle 1 & 2: Basal culture medium + activated sludge 30 mg/l + test chemical (100 mg/l); Bottle 3: Basal culture medium + activated sludge 30mg/l+ aniline (100mg/l) and Bottle 4: Basal culture medium + activated sludge 30 mg/l. Reference substance undergoes 61% degradation in 28 days. The percentage degradation of test substance (2E)-2-(phenylmethylidene)heptanel was determined to be 90% by BOD parameter in 28 days.Thus, based on percentage degradation, (2E)-2 -(phenylmethylidene)heptanal is considered to be readily biodegradable in nature.

 

In an supporting study from authoritative database (J-CHECK, 2017), biodegradation experiment was conducted for 28 days for evaluating the percentage biodegradability of test substance (2E)-2-(phenylmethylidene)heptanal (CAS no. 122-40-7).The study was performed according to OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I)). Concentration of inoculum i.e, sludge used was 30 mg/l and initial test substance conc. used in the study was 100 mg/l, respectively. The percentage degradation of test substance (2E)-2-(phenylmethylidene)heptanal was determined to be 51 and 81% by BOD and TOC removal parameter in 28 days. Thus, based on percentage degradation, (2E)-2 -(phenylmethylidene)heptanal is considered to be readily biodegradable in nature.

 

Another biodegradation study was conducted according to OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test) under aerobic condition for 28 days for evaluating the percentage biodegradability of test substance (2E)-2-(phenylmethylidene)heptanal (CAS no. 122-40-7) (HSDB, 2017). Secondary effluent from an unacclimatized activated sludge was used as a test inoculum. 10-day window criteria has been fulfilled. The percentage degradation of test substance (2E)-2-(phenylmethylidene)heptanal was determined to be 10 and 65% by CO2 evolution parameter after 10 and 28 days, respectively. Thus, based on percentage degradation, (2E)-2-(phenylmethylidene)heptanal is considered to be readily biodegradable in nature.

 

In an supporting study from peer reviewed journal (A.M. Api et. al, 2015), biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of test substance (2E)-2-(phenylmethylidene)heptanal (CAS no. 122-40-7). The study was performed according to OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test). The percentage degradation of test substance (2E)-2 -(phenylmethylidene) heptanal was determined to be 70.5% by CO2 evolution parameter in 28 days. Thus, based on percentage degradation, (2E)-2 -(phenylmethylidene)heptanal is considered to be readily biodegradable in nature.

 

For the target chemical(2E)-2-(phenylmethylidene)heptanal(CAS No. 122-40-7), Biodegradation study was conducted according to Commission Directive 79/831/EWG annex V part C method for 28 days for evaluating the percentage biodegradability of test substance (2E)-2-(phenylmethylidene)heptanal (A.M. Api et. al, 2015). The percentage degradation of test substance (2E)-2-(phenylmethylidene)heptanal was determined to be41% in 28 days. Thus, based on percentage degradation, (2E)-2 -(phenylmethylidene)heptanal is considered to be inherently biodegradable in nature.

 

Environmental fate

According to the fugacity model levels III, the most likely environmental fate for this test chemical is soil (i.e.estimated to 74.5%). In soil, 2-benzylideneheptanal was expected to have slow mobility based upon a LogKOC in the range 2.80 – 2.83. Thehalf-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, 24.5% of the chemical will partition into water according to the Mackay fugacity model level III in EPI suite version 4.1 (2017). 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).

 

In a supporting study from secondary source (Robust Summaries & Test Plans: Cinnamyl Derivatives: Revised Summaries, 2005), half-life of the chemical (2E)-2 -(phenylmethylide ne)heptanal (CAS No: 122-40-7) in water, sediment and soil was estimated by using Mackay EQC Fugacity Level III. The following values has been used in the Mackay EQC Fugacity Level III for the estimating the half-life value. They are water solubility: 8.5 mg/l, vapour pressure: 0.0012 mm Hg, log Kow: 4.7 and melting point: 80°C, repsecitvely. If released into the environment, 32.6% of the chemical will partition into water according to the Mackay EQC Fugacity Level III and the half-life period of (2E)-2 -(phenylmethylidene)heptanal is estimated to be 15 days (360 hrs) in water; 58.33 days (1400 hrs) in sediment and 15 days (360 hrs) in soil. The half-life (as estimated by Mackay EQC Fugacity Level III) indicates that the chemical (2E)-2 -(phenyl methylidene)heptanal is not persistent all three compartments.

 

Hence it has been concluded that 2-benzylideneheptanal 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:

 

Theestimated BCF value from authoritative database was determined to be in the range 334 - 1200.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 estimations for invertebrates and algae for the substance indicates the LC50/EC50 value to be in the range 0.28 – 3.14 mg/L. These value suggest that the substance is likely to be hazardous to Aquatic organisms at environmentally relevant concentrations and can be considered as classified in ‘Aquatic acute category 1’ as per the CLP regulation

 

Long-term toxicity evaluation in invertebrates is available for 2-benzylideneheptanal. The 21 day NOEC value for Daphnia magna is reported as 0.041 mg/L.

This value in conjunction with the biodegradability of the substance indicates that it can be considered as classified in ‘Aquatic chronic category 2’ as per the CLP regulation

 

Based on the data mentioned above, the chemical was not considered as hazardous to aquatic environments as per the criteria set out in Annex XIII since the NOEC for aquatic organisms for the substance is more than 0.01 mg/L.

 

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.