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Source: Beratergremium für umweltrelevante Altstoffe (BUA) Vol:226 (2001) 71 p Abstract:

Ecological Aspect. The only manufacturer of monochloroacetone in Europe is Wacker Chemie GmbH in Burghausen (Germany); one other manufacturer is located in India. The sole European manufacturer produces about 500 -1000 tonnes/year; no figures are available from the Indian manufacturer. Due to the various possibilities for synthesizing heterocyclic compounds, monochloroacetone is used mainly as a building block in the synthesis of pharmaceuticals and plant-protection agents. Other applications concern the formulation of emulsifiers, tanning agents, fragrances, antioxidants, enzyme activators, and photosensitizers. Figures are not available on the quantities used in these areas. According to the manufacturer, no emissions, wastewater, or wastes occur through production in a closed system. No data are available on introductions into the atmosphere, hydrosphere, geosphere, or biosphere through processing or application. Due to the lack of data on introductions into the various environmental media, no statement can be made on the balance of introductions. Little information is available on the occurrence in the environment. A 1979 publication reported air concentrations of 0.004 - 0.01 mg/m3 (=1.0 - 2.6 ppb) in the area of Jones State Forests (Texas). No data are available on the occurrence in the hydrosphere or geosphere. Monochloroacetone was qualitatively identified as a natural component of mazzard cherries (Prunus avium). Test results (closed bottle test according to OECD 301 D) have shown monochloroacetone to be non-biodegradable (0 % after 28 days). [The applicant remarks that the biodegradation rate was not correctly calculated in the test report. Recalculations revealed 59% after 28 days.] However, various other investigations indicate a degradation of monochloroacetone by bacteria, yeasts, and enzymes. With respect to the abiotic degradation in the atmosphere, monochloroacetone should be classified as barely degradable. It has no chromophoric components. However, as the absorption maximum in the UV spectrum is lambda = 292 nm, some weak photolysis cannot be excluded completely. For photochemical-oxidative degradation, a reaction rate constant of 0,3682E-12 cm3 x molecules-1 x s-1 was calculated by the AOPWIN program at room temperature. At an assumed OH-radical concentration of 5E5 molecules/cm3, this gives a half-life of 43.6 days. The experimentally determined hydrolytic rate of k = 8E-6 (1/h) at 25 degrees C indicates the substance to be stable in water. The half-life of an added concentration of 0.01 M was calculated to be 989 years. For the bioconcentration of monochloroacetone in aquatic organisms, a log BCF of approximately 2.6 - 3.2 can be calculated. Due to the hydrophilic nature of the compound, there thus appears to be little likelihood of bioconcentration in aquatic organisms. Sorption values of 1.2 -1.3 for soils and sediments can be calculated from the octanol-water partition coefficients, so that very little sorption to organic matter in soils and sediments may be assumed. The data on vapor pressure at room temperature vary between 14.6 and 42 hPa and are seen to be considerable. The solubility in water at room temperature is between 100 -124 g/l; data for Henry's law constants at room temperature are 1.7 - 3.13 Pa x m3/mol. Thus, the volatilization of monochloroacetone from an aqueous solution is classified as moderate. The calculation of the equilibrium distribution into target compartments according to Mackay level 1 gives 57.7 % for air and 42.3 % for water; soil, sediment, and biota make up 1 %. Valid data for an ecotoxicological assessment are sparse: Investigations on golden orfe (Leuciscus idus) to determine the acute fish toxicity according to DIN 38412, Part 15, gave the following 48-hour mortality values (nominal) in a semistatic test: 48-h LC0 = 0.2 mg/l, 48-h LC50 = 0.6 mg/l, 48-h LC100 = 1.6 mg/l. In toxicity studies on guppies (Poecilia reticulata), an LC50 of 0.7 mg/l was determined in a 14-day test. In a cell growth inhibition test according to DIN 38412, Part 8, with Pseudomonas putida the following values were determined for the 16-hour incubation time: 16-h EC10 = 0.14 mg/l, 16-h EC50 = 2.00 mg/l. Tests are not available on the ecotoxicity to algae or daphniae. Thus, the ecotoxicity results at hand do not yet allow an assessment of the environmental relevance.