Chloroethylene

Endpoint summary

Additional information

Photo transformation in air

The atmospheric half-life versus reaction with the hydroxyl radical (OH) is 2.3 days. The reaction with hydroxyl radical is the major sink of vinyl chloride. The atmospheric half-life versus reaction with ozone is 45 days. The reaction with ozone is a minor sink. The atmospheric half-life versus reaction with the nitrate radical is 155 days, which is a negligible sink. Direct photolysis negligible in the atmosphere. The reaction with the chlorine atom is negligible in the atmosphere, except possibly in the marine boundary layer. The reaction with the ground-state oxygen atom is negligible in the atmosphere. Overall the atmospheric half-life is 2.2 days. The main primary atmospheric degradation product from reaction with ozone is formyl chloride. Other products are formaldehyde, HCl, CO, CO2, formic acid, etc.

Hydrolysis

Hydrolysis is not expected to be a relevant dissipation route for vinyl chloride in water. Due to the fact that vinyl chloride is a gas, rapid volatilisation is expected and no significant concentrations are present in the fresh water and seawater compartment. This is supported by exposure assessment with EUSES. A regional PEC in fresh surface water of 4.18E-06 mg/L and a regional PEC in seawater of 3.44E-07 mg/L were calculated. The maximal local PEC value that was calculated for fresh water was 3.66E-02 mg/L (for S-PVC production). The maximum local PEC value that was calculated for seawater was 3.66E-03 mg/L (for S-PVC production). Since these concentrations are very low, hydrolysis is not considered to be relevant.

Biodegradation

Various biodegradation tests were performed with vinyl chloride. Although vinyl chloride was not found ready biodegradable under the rigid test conditions of the MITI test (16% after 28 days) or the test from the U.S. EPA (1977) as described in ATSDR (2006) in which the BOD of raw sewage seed was compared with BOD of raw sewage seed with vinyl chloride (no biodegradation observed), more recent data (summarised in section 5.2.3) demonstrated that vinyl chloride degrades well under specific conditions. In ground water, vinyl chloride degraded for almost 100% after 108 days under aerobic conditions (Davis and Carpenter, 1990). In anaerobic microcosms with methanogenic bed sediments, 98% biodegradation was found after 70 days. Degradation products were carbon dioxide, methane, ethane and ethene (Bradley, 1999). Furthermore, under aerobic conditions vinyl chloride degraded completely in two short term tests using adapted inoculum (Hartman 1985; Fogel 1986). Taken these studies into account, vinyl chloride is regarded biodegradable under specific environmental conditions.

Bioaccumulation

In accordance with column 2 of REACH Annex IX, the bioaccumulation study does not need to be conducted as the substance can be expected to have a low potential for bioaccumulation (log Kow < 3).

Adsorption/desorption

In accordance with column 2 of REACH Annex VIII, the adsorption/desorption study does not need to be conducted as the substance can be expected to have a low potential for adsorption (log Kow < 3). Furthermore, the endpoint is not considered relevant because vinyl chloride is a gas. With Pckocwin v1.66 a Koc value of 24 was calculated.