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Environmental fate & pathways

Biodegradation in water: screening tests

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Description of key information

The ready biodegradability ofCitronellyl Isobutyrate (CAS no. 97-89-2) was determined by the OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test), EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test) and EPA OPPTS 835.3110 (Ready Biodegradability), respectively for 34 days (Sustainability Support Services has a letter of access, 2012). Fresh activated sludge from a biological waste water treatment plant treating predominantly domestic sewage was used. The sludge is collected in the morning, washed three times in the mineral medium (by centrifuging at 1000 g for 10 minutes, discarding the supernant and resuspending in mineral medium) and kept aerobic until being used on the same day. Initial test substance concentration used in the study was 30 mg/l. Mineral medium was prepared by mixing 50 ml of solution A and 2000 ml deionised water, adding 5 ml of each of the solutions B, C and D and making up to 5 litres with deionised water. The pH is measured and if necessary adjusted to 7.4 +/- 0.2 with phosphoric acid or potassium hydroxide. The water used during this study is deionised water containing less than 10 mg/l dissolved organic carbon. Suspended solids concentration used in the study was 5.46 g/l diluted to 1.53 g/l dry matter. Sodium benzoate (100 mg/l) (purity min. 99.0%) was used as a reference substance for the study. Degradation of sodium benzoate exceeded 40% after 7 days and 65% after 14 days. Citronellyl Isobutyrate undergoes 75% biodegradation after 28 days in the test conditions. The 10 day window criterion is also fulfillled (15% biodegradation on day 2 and 69% biodegradation on day 12). Citronellyl Isobutyrate did not inhibit the intrinsic respiration of the inoculum at the test concentration and was therefore considered to be non-toxic to the inoculum at the test concentration. Thus, Citronellyl Isobutyrate should be regarded as readily biodegradable according to the test.

Key value for chemical safety assessment

Biodegradation in water:
readily biodegradable

Additional information

The ready biodegradability ofCitronellyl Isobutyrate (CAS no. 97-89-2) was determined by the OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test), EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test) and EPA OPPTS 835.3110 (Ready Biodegradability), respectively for 34 days (Sustainability Support Services has a letter of access, 2012). Fresh activated sludge from a biological waste water treatment plant treating predominantly domestic sewage was used. The sludge is collected in the morning, washed three times in the mineral medium (by centrifuging at 1000 g for 10 minutes, discarding the supernant and resuspending in mineral medium) and kept aerobic until being used on the same day. Initial test substance concentration used in the study was 30 mg/l. Mineral medium was prepared by mixing 50 ml of solution A and 2000 ml deionised water, adding 5 ml of each of the solutions B, C and D and making up to 5 litres with deionised water. The pH is measured and if necessary adjusted to 7.4 +/- 0.2 with phosphoric acid or potassium hydroxide. The water used during this study is deionised water containing less than 10 mg/l dissolved organic carbon. Suspended solids concentration used in the study was 5.46 g/l diluted to 1.53 g/l dry matter. Sodium benzoate (100 mg/l) (purity min. 99.0%) was used as a reference substance for the study. Degradation of sodium benzoate exceeded 40% after 7 days and 65% after 14 days. Citronellyl Isobutyrate undergoes 75% biodegradation after 28 days in the test conditions. The 10 day window criterion is also fulfillled (15% biodegradation on day 2 and 69% biodegradation on day 12). Citronellyl Isobutyrate did not inhibit the intrinsic respiration of the inoculum at the test concentration and was therefore considered to be non-toxic to the inoculum at the test concentration. Thus, Citronellyl Isobutyrate should be regarded as readily biodegradable according to the test.