Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

The substance, 2,6 -dimethylheptan-4 -one (diisobutyl ketone) has a predicted atmospheric half-life of 22 hrs., based on estimated second-order rate constant with photochemically-generated hydroxyl radical. Although the substance can absorb UV light at wavelength > 290 nm, making it potentially susceptible to direct photolysis, this mode of degradation via indirect photolysis ie expceted to be the dominant process affecting fate and lifetime of the substance in the atmosphere.

Diisobutyl ketone is an aliphatic ketone, possessing only the carbonyl (ketone) and aliphatic carbon functional groups. As such, the substance is not susceptible to hydrolytic degradation under the pH and temperature typical of physiological or environmetnal conditions.

As stated for the atomosphere, the substance may be susceptible to direct photolysis in surface waters and soils because it can absorb UV light at wavelengths > 290 nm. However, biodegradation is expected to be the dominant process affecting the fate and lifetime of this substance in aerobic surface water, soil, sediment, and groundwater environments. The substance was shown to be readily biodegradable, exhibiting a high degree of degradation and short lag period before its onset, using a non-adapted and very dilute inoculum. By OECD definition, this and any readily biodegradable substance can be expected to rapidly and ultimately biodegrade in a variety of aerobic environments.