3-chloropropene

Endpoint summary

Additional information

3-chloropropene can be considered as a volatile compound. Results from a Mackay Level I fugacity model indicate that 99.35 % of the mass released to the environment will partition into the atmosphere (OECD 1996). In addition, 3-chloropropene will be emitted mainly into the atmosphere. If 3 -chloropropene is emitted into water it will rapidly volatilise to the air. Model calculations for a river indicate an evaporation half-life of approximately 3 hours (OECD 1996). Under experimental conditions which included 250 mL vessels, concentrations of 1 ppm, 200 rpm stirring of the test solution, still air and a solution depth of 6.5 cm, the evaporation half-life was approximately 30 minutes (Dilling 1977). It is well known that 3-chloropropene is effectively removed from the atmosphere by indirect photochemical reactions, e.g. with OH-radical. The removal of the substance from the atmosphere by reaction with photochemically produced OH- and NO3-radical and ozone was tested in accordance to methods similar to those laid down in the relevant US EPA guidelines by using a well-documented and extensively tested method of the Statewide Air Pollution Research Center (California) involving the use of Teflon-coated or all-Teflon environmental chambers or reaction bags (Winer and Atkinson 1987). The OH radical was generated by applying light at wavelengths of greater 290 nm from a Xenon arc (12 hours daytime) with methyl nitrite. The disappearance of organic reactants was monitored by gas chromatography and/or long pathlength Fourier transform absorption spectroscopy. The reaction products of OH-radical initiated reactions were investigated by using FT-IR spectroscopy or off-line GC or GC-MS analysis. The experiments showed that 3-chloropropene is removed from the atmosphere mainly by OH-radical induced reaction with a half-life of 1.4 days. The dissipation half-life for reaction with ozone was 10 days and the half-life for reaction with NO3-radical was 160 days. The major reaction products of the chemical reaction of 3-chloropropene with the three chemical species are formaldehyde, hyprochloric acid, glycolaldehyde, chloroacetaldehyde and peroxynitrates and nitrates.

3-chloropropene is also water-soluble. The available data indicate that 3-chloropropene is hydrolysed in water to give biodegradable alcohols. The half-life for hydrolysis of 3-chloropropene is approximately 8 to 12 days (Miller 1982, Krijgsheld et al. 1986).

The ready biodegradability of 3-chloropropene was studied in a modified MITI test (I) (CITI 1992). The concentration of the test substance at the start of the test was 100 mg/L. The concentration of the activated domestic sludge was 30 mg/L. The cultivation temperature was 25 °C. The test was performed for 28 days. The degradation of the test material was measured by monitoring the BOD, TOC and analysing the test material using gas chromatography. The removal of 3-chloropropene (based on BOD) was between 55 and 69 % after 28 days. Analysis of TOC resulted in a similar level, whereas analysis of the test substance indicated that 95 % of the substance had disappeared. The substance was characterised as readily biodegradable on the basis of the MITI test (I). The potential biodegradability of 3-chloropropene was also indicated in a test by determining the BOD and COD for test solutions seeded with effluent from a biological sanitary waste treatment plant according to APHA Standard Methods No 219 and ASTM standard D 1252-67 (Bridie et al. 1979). The test resulted in a BOD in relation to the theoretical oxygen demand after five days of 14 % and 25 % with non-adapted and adapted seed, respectively.

The bioaccumulation of 3-chloropropene was tested for 42 days in accordance with OECD Guideline No 305C in a flow-through system with Cyprinus carpio at concentrations of 0.05 and 0.5 mg/L (CITI 1992). The analytical method for the determination of the test substance was gas chromatography. The bioconcentration factors were <5.6 and <0.88 at the two concentrations, respectively. This indicates that 3-chloropropene has a low tendency for bioaccumulation. This is supported by the low Kow-value of 1.93 obtained by using the US Environmental Protection Agency modelling program KOWWIN V4.0 (Anonymous 2009) and by the low Koc-value of 47 obtained by using the US Environmental Protection Agency modelling program KOCWIN V2.0 (Wormuth 2009).