Acetone

Endpoint summary

Additional information

Deduced as a weight of evidence from the physicochemical data (miscibility with water in all proportions, log Pow = -0.24) acetone should not sorb onto soils. Data for soil sorption are quoted in a reliable scientifical study. Soil sorption Kd was 1.5 L/kg, at 20 °C. The soil sorption coefficient indicates that acetone is mobile in soil and may be transported by soil water. This study is supported by two other findings. In an adsorption/desorption study with the clay mineral sodium montmorillonite no adsorption of acetone was observed. Sodium montmorillonite is part of the clay fraction of soils. Therefore it can be concluded that acetone does not sorb on mineral fractions of soils. In a further study on anaerobic biodegradation of¹⁴C labelled acetone in landfill refuse, the soil was intensively extracted after the experiment. The study shows that acetone is able to percolate through landfill refuse caused by rainfall, despite anaerobic biodegradation occurred. Traces of¹⁴C were found in the humin fraction of the refuse, but nature and bonding of these residues were not studied. No physically adsorbed¹⁴C-acetone was found in the CH₂Cl₂-extracts of the samples percolated with water, and only traces of¹⁴C-acetone were found in the samples that were not percolated by water, indicating the low adsorption potential of¹⁴C-acetone.

 

Several reliable experimental studies and further reported values for the Henry’s Law constant are available. According to reliable experimental studies (bubble column technique) the Henry’s Law constant was determined for 2.929 Pa m³mol^-1and 3.070 Pa m³mol^-1at 25 °C, indicating a moderate volatility from water.

The Henry's law constant for sea water was determined for 3.311 Pa m³mol^-1at 25 °C. A slight salting-out effect is to be observed by comparison of the Henry's Law constants in fresh and sea water. In both media the Henry's law constants rise with temperature.

 

Distribution modelling using a simple one-dimensional model of the global circulation assuming a single pulse emission of acetone predicted significantly high spatial ranges of 46.5% of the earth perimeter, which are caused by their intermediate gas-phase stability and high volatility. The persistence’s are predicted below 20 days, mainly due to the degradation in water and soil.

 

A generalised Fate Model based on a steady-state mass balance model designed for primary and biological reactors of a typical diffused air activated sludge system considering the processes advection, sorption, volatilisation, air stripping, and biotransformation was used to predict the fate of acetone in waste water plants. The model calculations implicate that acetone is predominantly in the aqueous phase and without biotransformation it would be transferred to the effluent. Volatilisation is not relevant. In model runs including biodegradation removal is partly due to biotransformation and to transport to the effluent.

 

There are several studies concerning other distribution data dealing with the partition of acetone between air and water and the behaviour in soils. Air/water partition coefficients range from 357 – 341:1, these data are in accordance with the moderate volatility of acetone deduced from the experimentally derived Henry’s Law constants. Other studies are dealing with the diffusion of acetone in soil air. Soil diffusion coefficient at 0 °C was calculated for 8.8 x 10^-3cm²/sec (air: 0.109 cm²/sec). The diffusion coefficient for acetone was found to be considerably lower than in air. Liquid acetone is able to expand clay soils rapidly within 2-3 days to an extent of 3.5 – 8 %.