Cinnamaldehyde

Endpoint summary

Description of key information

Biodegradation in water

Biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of test chemical. The study was performed by a modified OECD screening test conducted as per the method similar to OECD Guideline 301 B (Ready biodegradability: CO2 evolution). Secondary effluent from a sewage treatment plant was usedas a test inoculum. A test chemical solution was inoculated with the test inoculum in a mineral medium in test flasks and incubated further for a period of 28 days. The percentage degradation of test chemical was determined to be 89%, 94% and 100% by using DOC removal parameter after a period of 7, 14 and 21 days. Thus, based on percentage degradation, test chemical was considered to be readily biodegradable in water.

Biodegradation in water and sediment

Estimation Programs Interface prediction model was run to predict the half-life in water and sediment for the test chemical. If released in to the environment, 31.8 % of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of test chemical in water is estimated to be 15 days (360 hrs). The half-life (15 days estimated by EPI suite) indicates that the chemical is not persistent in water and the exposure risk to aquatic animals is low whereas the half-life period of test chemical in sediment is estimated to be 135 days (3240 hrs). However, as the percentage release of test chemical into the sediment is less than 1 % (i.e, reported as 0.107 %), indicates that test chemical is not persistent in sediment.

Biodegradation in soil

The half-life period of test chemical in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database. If released into the environment, 67.6 % of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of test chemical in soil is estimated to be 30 days (720 hrs). Based on this half-life value of test chemical, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is low.

Additional information

Biodegradation in water

Various experimental studies of the target chemical were reviewed for the biodegradation end point which are summarized as below:

 

Biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of test chemical. The study was performed by a modified OECD screening test conducted as per the method similar to OECD Guideline 301 B (Ready biodegradability: CO2 evolution). Secondary effluent from a sewage treatment plant was usedas a test inoculum. A test chemical solution was inoculated with the test inoculum in a mineral medium in test flasks and incubated further for a period of 28 days. The percentage degradation of test chemical was determined to be 89%, 94% and 100% by using DOC removal parameter after a period of 7, 14 and 21 days. Thus, based on percentage degradation, test chemical was considered to be readily biodegradable in water.

In an experimental study from study report (2018),biodegradation experiment was conducted for 28-days following the OECD guideline 301 D for determining the ready biodegradability of the test chemical. The study was performed at a temperature of 20°C under aerobic conditions. Aerobic conditions was provided by means of mineral media which is aerated for 20 hours prior to start of the experiment. The test system included control, test chemical, reference substance and toxicity control. Polyseed capsule (mixed culture) was used as a test inoculum for the study. Test inoculum polyseed capsule was composed of blend of specialized microbial cultures and food grade gelatin made by International Laboratory Supply (InterLab), LTD. No pretreatment / preconditioning was given to the test inoculum as the polyseed capsule requires only one hour of stirring to activate it. 1 Polyseed capsule was added in 500 mL DI water and then stirred for 1 hour for proper mixing and functioning of inoculum & settled for 15 minutes to eliminate the bran. Decanted polyseed solution was used as mixed inoculum. Thus, concentration of test inoculum used for the study was 32 ml/l which corresponds to 10E7 to 10E8 CFU/ml. The concentration of test and reference substance (Sodium Benzoate) chosen for both the study was 4 mg/L. OECD mineral medium was used for the study. ThOD (Theoretical oxygen demand) of test and reference chemical was determined by calculation. % degradation was calculated using the values of BOD and ThOD for test chemical and reference substance. The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 61.44%. 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 BOD14 value of test chemical was observed to be 1.525 mgO2/mg. ThOD was calculated as 2.54 mgO2/mg. Accordingly, the % degradation of the test chemical after 14 and 28 days of incubation at 20 ± 1°C according to Closed Bottle test was determined to be 61.02% & 57.08%. Overall, the test chemical under the test conditions, was considered to be readily biodegradable in nature.

 

In a supporting weight of evidence study from peer reviewed journal (2019), biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of test chemical. The study was performed by a modified OECD screening test conducted as per the method similar to OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test). Secondary effluent from a sewage treatment plant was used as a test inoculum. A test chemical solution was inoculated with the test inoculum in a mineral medium in test flasks and incubated further for a period of 28 days. The percentage degradation of test chemical was determined to be 89%, 94% and 100% by using DOC removal parameter after a period of 7, 14 and 21 days. Thus, based on percentage degradation, test chemical was considered to be readily biodegradable in water.

 

Additional biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of test chemical (A. M. Api et. al; 2019). The study was performed in accordance with the OECD Guideline 301 F (Ready biodegradability: Manometric Respirometry Test) at 22°C. Activated sludge obtained from a wastewater treatment plant was used as a test inoculum. Test chemical concentration used for the study was 100 mg/l. A test chemical solution was inoculated with the test inoculum in a mineral medium and incubated further for a period of 28 days. The percentage degradation of test chemical was determined to be 86% by using oxygen consumption parameter after 28 days. Thus, based on percentage degradation, test chemical was considered to be readily biodegradable in water.

 

For the test chemical, biodegradation study was conducted for evaluating the percentage biodegradability of test chemical (from handbook, 2008 and secondary source, 1991). River water was used as a test inoculum. It was acclimated for 100 days. The percentage degradation of test chemical was determined to be 88% by using oxygen consumption parameter after 10 days. Thus, based on percentage degradation, test chemical was considered to be readily biodegradable in water.

 

In a supporting weight of evidence study, biodegradation experiment was conducted for determining the biodegradability of test chemical (Study report, 2015). Mixed inoculum was used as a test inoculum. The inoculum used was a diluted suspension of mixed inoculum at a concentration of 0.5 ml/L. The test system included control, test substance and reference substance. Initial test chemical concentration used for the study was 2 mg/l while that of inoculum (diluted suspension of mixed inoculum) was 0.5 ml/l. This gave the bacterial CFU/ml as 104E to 10E6. The study was performed under aerobic conditions at 20 ± 2°C for 5 days. DO determination on the 0th and 5th day of the experiment was done with the help of DO meter. The amount of oxygen taken up by the microbial population during biodegradation of the test substance was corrected for uptake by the blank inoculum and BOD5 was calculated accordingly. ThOD, BOD5 and % Degradation of both reference and the test substance were then calculated. Sodium acetate (5 mg/l) was used as a reference substance for the study and undergoes 127.65% degradation after 5 days. The BOD5 value of test chemical was observed to be 0.635 mgO2/mg. ThOD was determined by calculation as 2.542 mgO2/mg. Accordingly, the % degradation of the test chemical after 5 days of incubation at 20°C was determined to be 24.98%. Thus, test chemical was considered to be biodegradable in water.

 

On the basis of above results, it can be concluded that the test chemical was considered to be readily biodegradable in water.

Biodegradation in water and sediment

Estimation Programs Interface prediction model was run to predict the half-life in water and sediment for the test chemical. If released in to the environment, 31.8 % of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of test chemical in water is estimated to be 15 days (360 hrs). The half-life (15 days estimated by EPI suite) indicates that the chemical is not persistent in water and the exposure risk to aquatic animals is low whereas the half-life period of test chemical in sediment is estimated to be 135 days (3240 hrs). However, as the percentage release of test chemical into the sediment is less than 1 % (i.e, reported as 0.107 %), indicates that test chemical is not persistent in sediment.

In addition to this, biodegradation in water and sediment endpoint can also be considered for waiver as per in accordance with column 2 of Annex IX of the REACH regulation, testing for this end point is scientifically not necessary and does not need to be conducted since the test chemical is readily biodegradable in water.

Biodegradation in soil

The half-life period of test chemical in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database. If released into the environment, 67.6 % of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of test chemical in soil is estimated to be 30 days (720 hrs). Based on this half-life value of test chemical, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is low.

 

In addition to this, biodegradation in soil endpoint can also be considered for waiver as per in accordance with column 2 of Annex IX of the REACH regulation, testing for this end point is scientifically not necessary and does not need to be conducted since the test chemical is readily biodegradable in water.