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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Biodegradation in water

Biodegradation study was conducted for 6 days for evaluating the percentage biodegradability of test chemical (from peer reviewed journal (H. Leidner et. al, 1980), authoritative databases (2017) and secondary source). The study was performed according to OECD Screening test.The study was performedunder aerobic conditions at a temperature of 20°C.Mixed culture isolated from soil was used as a test inoculum for the study. Initial test substance conc. used in the study was 8 mg/l. Erlenmeyer flasks were used as a test vessel for the study. Test inoculum i.e, mixed microbial biocenosis(a community of various species of organotrophic microorganisms) was prepared by diluting a suspension of garden soil. 2 l of mineral salt medium containing the test chemical as a sole source of carbon were inoculated with 2ml of a mixed culture. The test vessels were incubated at 20°C with continuous stirring. Degradation of test chemical was determined by DOC, GC and HPLC analysis. For Gas chromatography analysis, sample preparation involve 50ml of the bioassay mixture were centrifuged for 15 min at 30,000 g to remove the biomass from the liquid. For GLC analysis, test chemical was esterified via their silver salts. The FID signal was electronically integrated (CRS-100AInfotronics, Ireland). n-Tridecane served as an internal standard in quantitative determinations.HPLC methods were also used to follow the degradation. ion pair partition chromatography on a bonded phasecolumn(250x4mm, packed with 5µsilica, chemically modified with dichlorodimethylsilane) was used as a separation column.A0.01Mtributylamine solution in methanol-water (1:2, v/v), titrated with perchloric acid to pH 2, served as the eluent. Varian 850 dual syringe pump instrument equipped with a variable wavelength detector (Varichrom, Varian) was used. The decreases in peak heights in proportion to the initial heights served as a relative quantitative measure for degradation.In additional to GC and HPLC,Dissolved organic carbon was also determined of the test chemical. For this,bacteria-free 50 ml samples were acidified with HCI. Dissolved organic carbon (dissolved organic compounds expressed as carbon) was determined with a carbon analyser 'Unor' (Maihak, Hamburg, FR Germany). Detection limit: -0.1 p.p.m. above background.The percentage degradation of test chemical was determined to be 100% by DOC, GC and HPLC parameter after a period of 3 days. Thus, based on percentage degradation,test chemical is considered to be readily biodegradable in nature.

Biodegradation in water and sediment

Estimation Programs Interface (2018) prediction model was run to predict the half-life in water and sediment for the test chemical. If released in to the environment, 26% 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 moderate to 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 0.0796%), 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 (2018). If released into the environment, 73.3% 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 moderate to low.

Additional information

Biodegradation in water

Various experimental key and supporting studies of the test chemical were reviewed for the biodegradation end point which are summarized as below:

 

In an experimental key study from peer reviewed journal (H. Leidner et. al, 1980), authoritative databases (2017) and secondary source,biodegradation experiment was conducted for 6 days for evaluating the percentage biodegradability of test chemical. The study was performed according to OECD Screening test. The study was performed under aerobic conditions at a temperature of 20°C.Mixed culture isolated from soil was used as a test inoculum for the study. Initial test substance conc. used in the study was 8 mg/l. Erlenmeyer flasks were used as a test vessel for the study. Test inoculum i.e, mixed microbial biocenosis(a community of various species of organotrophic microorganisms) was prepared by diluting a suspension of garden soil. 2 l of mineral salt medium containing the test chemical as a sole source of carbon were inoculated with 2ml of a mixed culture. The test vessels were incubated at 20°C with continuous stirring. Degradation of test chemical was determined by DOC, GC and HPLC analysis. For Gas chromatography analysis, sample preparation involve 50ml of the bioassay mixture were centrifuged for 15 min at 30,000 g to remove the biomass from the liquid. For GLC analysis, test chemical was esterified via their silver salts. The FID signal was electronically integrated (CRS-100AInfotronics, Ireland). n-Tridecane served as an internal standard in quantitative determinations. HPLC methods were also used to follow the degradation. ion pair partition chromatography on a bonded phase column(250x4mm, packed with 5µsilica, chemically modified with dichlorodimethylsilane) was used as a separation column.A0.01Mtributylamine solution in methanol-water (1:2, v/v), titrated with perchloric acid to pH 2, served as the eluent. Varian 850 dual syringe pump instrument equipped with a variable wavelength detector (Varichrom, Varian) was used. The decreases in peak heights in proportion to the initial heights served as a relative quantitative measure for degradation. In additional to GC and HPLC, Dissolved organic carbon was also determined of the test chemical. For this, bacteria-free 50 ml samples were acidified with HCI. Dissolved organic carbon (dissolved organic compounds expressed as carbon) was determined with a carbon analyser 'Unor' (Maihak, Hamburg, FR Germany). Detection limit: -0.1 p.p.m. above background. The percentage degradation of test chemical was determined to be 100% by DOC, GC and HPLC parameter after a period of 3 days. Thus, based on percentage degradation, test chemical is considered to be readily biodegradable in nature.

 

Another biodegradation study was conducted for 20 days for evaluating the percentage biodegradability of test chemical (R. V. Subba-Rao et. al., 1977). The study was performed under aerobic conditions at a temperature of25°C.Bacteria obtained from Hudson Collamer silt loam was used as a test inoculum for the study. The chemical was introduced into the BOD bottles as a source of carbon at a concentration of 2 mg of carbon per bottle. Test chemical was added in the acetone solutions, and the acetone was evaporated prior to the addition of O2-saturated water. Each bottles received 5 mg of Hudson Collamer silt loam as a source of the microbial inoculum. The bottles were filled with the air-saturated salts solution and closed with glass stoppers. Bottles containing 02-saturated water inoculated with soil but no carbon source were also included in the study to account for theO2depletion resulting from microbial oxidation of organic matter and ammonium. Each compound was also tested in combination with glucose (both at a concentration of 2 mg of carbon per bottle) to test whether the possible lack of biodegradation was a result of toxicity of the test chemical. The bottles were incubated in the dark at 25°C.Dissolved O2 in the bottles was measured at regular intervals using a Yellow Spring Instrument Co. (Yellow Springs, Ohio) oxygen analyzer, Model 53. The instrument was calibrated with the salts solution, theO2content of which was determined by the Alsterberg modification of the Winkler method (American Public Health Association, 1971). At regular intervals, the dissolved O2 in the samples was measured after calibrating the instrument with a BOD bottle containing inoculated 02-saturated water supplemented with 0.1% KCN. The solutions in bottles showing O2depletion were used to obtain microorganisms capable of utilizing the substrate. The BOD5 of the test chemical was determined to be approx. 5.4 O2 consumed µg/ml. Thus, based on this, test chemical is considered to be readily biodegradable in nature.

 

In a supporting study from peer reviewed journal (W. R. Mayberry et. al., 1967),biodegradation experiment was conducted for evaluating the percentage biodegradability of test chemical. The study was performed at a temperature of 30°C. Test bacterial inoculum (Pseudomonas C12B and TEG-5) obtained from soil was used as a test inoculum for the study. Cells were adapted to the test substrates by three transfers into a basal salts medium containing the compound of interest at a concentration of 0.25%, w/v, with incubation at 30°C on a rotary shaker. Adapted cells were harvested by centrifugation (37,000 X g for 30 min) of late-log-phase cultures, and washed twice with sterile basal salts medium to remove soluble substrates. The substrate-free cells were then reharvested and washed twice with sterile basal salts. Washed adapted cells from the various cultures were resuspended in the sterile mineral medium to an optical density of 0.65 at 420 ml,. Portions of 0.5 ml each were used as inocula. Test chemical conc. used for the study were 20, 40, 60 and 80 µM per 30 ml, respectively. Basal salt medium was used as a test medium for the study. Warburg flasks were used as a test vessel. Test was performed in 4 replicates. Replicate sets of four flasks containing a fourfold range of substrate concentrations, approximately 20, 40, 60, and 80 µmoles per 30 ml, were prepared with 0.5 ml of 50% KOH in the center wells to trap carbon dioxide. Inocula were placed in the side arms, bringing the total fluid volume to 31 ml and the total culture volume to 30.5 ml. After equilibration at 30 C, the cells were tipped in and oxygen uptake was followed manometrically as the bacteria multiplied until semilogarithmic plots of oxygen uptake versus time were no longer linear. Flasks were removed from the apparatus, cell crops determined, and the media analyzed for residual substrate and possible end products of metabolism. Concentration of the test chemical was determined in all cases by calculation of the ratio of the peak area for the compound of interest to the peak area for the internal standard. For each substrate, a standard curve was established relating the peak area ratios to concentrations encompassing a range of 0.5 to 20 µmoles per 30 ml. In all cases, substrate utilized was considered to be the difference between original and residual concentrations. The 95% confidence intervals were calculated by Student's t formula. The percentage degradation of test chemical was determined to be 82.21% by using Test material analysis (% degradation) parameter. Thus, based on percentage degradation, test chemical is considered to be readily biodegradable in nature.

 

For the test chemical, biodegradability of test chemical was estimated using the BIODEG linear and non-linear model (E. Rorije et. al., 1997). The models have been applied are Quantitative Structure-Activity Relationships. Two models are fitted to the judgement of an evaluation of various different biodegradation rates of chemical. This include the one using linear regression and other using a form of non-linear fitting. These models used 36 fragments as descriptors with the molecular weight of the molecule as an added descriptor, and are fitted on the evaluated biodegradation data of a series of 295 compounds. The output of the models, x, is the number that should be interpreted as x < 0.5 (=0) (Chemical biodegrades slowly or not at all) or x > 0.5 (=1) (Chemical biodegrades fast), respectively. These tests typically produce ‘biodegradable’ (1) or ‘non-biodegradable’ (0) as a result. The application of the models has been automated, the BIODEG models are incorporated in the PC-based program. As the biodegradability prediction of test chemical by the BIODEG models comes out to be 1, test chemical is estimated to be readily biodegradable in nature.

In last study,35-days Closed Bottle test following the OECD guideline 301 D was performed to determine the ready biodegradability of test chemical. The test system included control, test item and reference item. The concentration of test and reference item ( Sodium Benzoate) chosen for both the study was 4 mg/L, while that of inoculum was 32 ml/l. 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 BOD35 value of Phenylacetic acid, CAS No. 103-82-2 was observed to be 1.22 mgO2/mg. ThOD was calculated as 2.11 mgO2/mg. Accordingly, the % degradation of the test item after 35 days of incubation at 20 ± 1°C according to Closed Bottle Test was considered to be 57.81%. Based on the results, the test item, under the test conditions, was considered to be ultimate inherently biodegradable in nature.

 

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

Biodegradation in water and sediment

Estimation Programs Interface (2018) prediction model was run to predict the half-life in water and sediment for the test chemical. If released in to the environment, 26% 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 moderate to 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 0.0796%), 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 (2018). If released into the environment, 73.3% 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 moderate to low.

On the basis of available information, the test chemicalcan be considered to be readily biodegradable in nature.