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Biodegradation in water

Biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of test substance Nonylphenol ethoxylates (CAS no. 127087 -87 -0) (NTRL report no. OTS0558989, 1997). 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. During the 28 day period the biological oxygen demand is measured and at the end of the 28 day period the level of organic carbon remaining in the aqueous phase is also measured. The percentage degradation of test substance was determined to be 81% by DOC removal parameter in 28 days. Thus, based on percentage degradation, Nonylphenol ethoxylates is considered to be readily biodegradable in nature.

Biodegradation in water and sediment

Estimation Programs Interface (EPI) Suite (2017) prediction model was run to predict the half-life in water and sediment for the test compound4-Nonylphenol, branched, ethoxylated(CAS No. 127087 -87 -0). If released in to the environment, 9.39% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of4-Nonylphenol, branched, ethoxylatedin water is estimated to be 60 days (1440 hrs). The half-life (60 days) indicates that the chemical is persistent in water and the exposure risk to aquatic animals is moderate to high whereas the half-life period of4-Nonylphenol, branched, ethoxylatedin sediment is estimated to be 541.66 days (13000 hrs). However, as the percentage release of test chemical into the sediment is less than 1% (i.e, reported as 0.631%), it can be considered that4-Nonylphenol, branched, ethoxylatedis not persistent in sediment.   

Biodegradation in soil

The half-life period of 4-Nonylphenol, branched, ethoxylated (CAS No. 127087 -87 -0) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2017). If released into the environment, 90% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of 4-Nonylphenol, branched, ethoxylated in soil is estimated to be 120 days (2880 hrs). Based on this half-life value of 4-Nonylphenol, branched, ethoxylated, 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

1 experimental study for the target compound Polyethylene glycol mono(branched p-nonylphenyl) ether(CAS No. 127087-87-0) which is supported further by the 2 weight of evidence studies (from peer reviewed journal and authoritative database) for its closest read across substance with logKow as the primary descriptor were reviewed for the biodegradation end point which are summarized as below:

 

In a weight of evidence study for target chemical Polyethylene glycol mono(branched p-nonylphenyl) ether(CAS No. 127087-87-0), biodegradation experiment was conducted for 28 days (NTRL report no. OTS0558989, 1997) 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. During the 28 day period the biological oxygen demand is measured and at the end of the 28 day period the level of organic carbon remaining in the aqueous phase is also measured. The percentage degradation of test substance was determined to be 81% by DOC removal parameter in 28 days. Thus, based on percentage degradation, Nonylphenol ethoxylates is considered to be readily biodegradable in nature.

Another weight of evidence study of biodegradation for read across substance Triethylene glycol ethyl ether (CAS no. 112 -50 -5) (having a 50 -60% similarity with the target chemical Polyethylene glycol mono(branched p-nonylphenyl) ether) was carried out for 20 days for evaluating the percentage biodegradability of chemical Triethylene glycol ethyl ether (Kenneth S. Price et. al; 1974) . Initial test substance conc. used in the study was 3, 7 and 10 mg/l, respectively. Domestic wastewater was used as a test inoculum.The BOD bottles were half filled with aerated dilution water containing the specified minerals and buffer. Small aliquots of the test chemicals were added to these bottles from 0.1% stock solutions yielding conc. of 3, 7 and 10 mg/l. At least two of these concentrations were tested in duplicate. These concentrations gave a potential oxygen demand of 3 to 30 mg/l over the 20 days duration of test. Dissolved oxygen was monitored periodically in the individual bottles through the use of a commercial DO meter filled with an agitated probe. The bottles were opened for sampling and DO measurements about five times during the course of the 20 day test.The percentage degradation of test substance was determined to be8, 47, 63 and 71% degradation in 5, 10, 15 and 20 days, respectively.Thus, based on percentage degradation,Triethylene glycol ethyl etheris considered to be readily biodegradable in nature.

For the same read across chemical Triethylene glycol ethyl ether (CAS no. 112 -50 -5) from authoritative database (J-CHECK, 2016), biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of test substanceTriethylene glycol ethyl ether (CAS no. 112 -50 -5). 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 was determined to103, 99 and 100% by BOD, TOC removal and GC parameter in 28 days. Thus, based on percentage degradation,Triethylene glycol ethyl ether is considered to be readily biodegradable in nature

On the basis of above results for target chemical Polyethylene glycol mono(branched p-nonylphenyl) ether(from NTRL report) and for its read across substance (from peer reviewed journal and authoritative database J-CHECK) , it can be concluded that the test substance Polyethylene glycol mono(branched p-nonylphenyl) ether can be expected to be readily biodegradable in nature.

Biodegradation in water and sediment

Estimation Programs Interface (EPI) Suite (2017) prediction model was run to predict the half-life in water and sediment for the test compound4-Nonylphenol, branched, ethoxylated(CAS No. 127087 -87 -0). If released in to the environment, 9.39% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of4-Nonylphenol, branched, ethoxylatedin water is estimated to be 60 days (1440 hrs). The half-life (60 days) indicates that the chemical is persistent in water and the exposure risk to aquatic animals is moderate to high whereas the half-life period of4-Nonylphenol, branched, ethoxylatedin sediment is estimated to be 541.66 days (13000 hrs). However, as the percentage release of test chemical into the sediment is less than 1% (i.e, reported as 0.631%), it can be considered that4-Nonylphenol, branched, ethoxylatedis not persistent in sediment.   

Biodegradation in soil

The half-life period of 4-Nonylphenol, branched, ethoxylated (CAS No. 127087 -87 -0) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2017). If released into the environment, 90% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of 4-Nonylphenol, branched, ethoxylated in soil is estimated to be 120 days (2880 hrs). Based on this half-life value of 4-Nonylphenol, branched, ethoxylated, 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 substance Polyethylene glycol mono(branched p-nonylphenyl) ether can be considered to be readily biodegradable in nature.