Registration Dossier

Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Biodegradation in water: screening tests

Ready biodegradability test was carried out to find biodegradation of chemical 3,7-dimethylocta-2,6-dienenitrile. As inoculum a mixture of (proportion) 1: 1 of municipal sludge from laboratory wastewater treatment plants fed with municipal sewage and sludge from BASF wastewater treatment plant was used. The concentration of the dry substance was 30 mg/l. After 35 days the test substance was degraded up to 100 % (BOD of ThOD). Hence, the test chemical 3,7-dimethylocta-2,6-dienenitrile was found to be biodegradable(10 days window was not covered)with 59% biodegradation in 10 days.

Biodegradation in water and sediment: simulation tests

Estimation Programs Interface (EPI) Suite (2016) prediction model was run to predict the half-life in water and sediment for the test compound Citralva (CAS No. 5146 -66 -7). If released in to the environment, 20.7 % of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of Citralva in water is estimated to be 15 days (360 hrs). The half-life (15 days estimated by EPI suite) indicates that the exposure risk to aquatic animals is moderate to low whereas the half-life period of Citralva 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 0.354%), indicates that Citralva is not persistent in nature.   

Biodegradation in soil

The half-life period of Citralva (CAS No. 5146-66-7) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2016. If released into the environment, 78.8% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of Citralva in soil is estimated to be 30 days(720 hrs).Based on this half-life value of Citralva, 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 Citralva can be considered to be readily biodegradable in nature

Adsorption / desorption:

Predicted data of adsorption endpoint for the target chemical 3, 7-dimethylocta-2, 6-dienenitrile (Cas no. 5146-66-7) and its read across chemical were reviewed to summarize as follows:  

From predicted model EPI suite 2016 indicate that the soil adsorption coefficient (Koc) value of chemical 3, 7-dimethylocta-2, 6-dienenitrile is estimated to be 420.8 L/kg (log KOC = 2.624) by means of MCI method at 25 deg.C.

Whereas from chemspider predicted database the soil adsorption coefficient i.e Koc value of test substance 3, 7-dimethylocta-2, 6-dienenitrile was estimated to be 2345.62 L/Kg i.e Log Koc= 3.370 at pH 5.5 and 7.4.

Based on the above both predicted Koc values indicate that the test substance 13, 7-dimethylocta-2, 6-dienenitrile (Cas no. 5146-66-7) has moderate tendency of sorption to soil and sediment and therefore have slow migration potential to groundwater.