1,2-dichloroethane

Report

To read the report please click here.

This marine risk assessment was also published in a peer-reviewed journal: De Rooij, C. et al., 1998. Euro Chlor risk assessment for the marine environment Osparcom region: North Sea – 1,2-dichloroethane. Environmental Monitoring and Assessment, Vol. 53, (3), 425-445.

Summary

Current usage of 1,2-dichloroethane poses no risk to the marine environment in the North Sea. This conclusion is based on 45 aquatic toxicity studies, together with 1991-95 North Sea analytical monitoring results.

Applications of 1,2-dichloroethane

The main use of 1,2-dichloroethane (EDC) - currently accounting for more than 95% of production - is to make vinyl chloride monomer (VCM) on which PVC is based. EDC is made from ethylene both by direct chlorination using chlorine and by oxychlorination in the presence of oxygen and hydrogen chloride (HCl). It is then transformed by pyrolysis into VCM and HCl.

The remaining EDC production (under 5% ) is used in three areas: as a raw material for manufacture of ethyleneamines, trichloroethylene and perchloroethylene; as an extraction and cleaning solvent; and as a lead scavenger for petrol.

Evaluation of environmental risk

For EDC, the evaluation of toxicity was based on seven sets of data for algae, 17 for invertebrates and 21 for fish in both marine and freshwater media. These were assessed using the environmental quality criteria recommended by the European authorities. Both acute and chronic toxicity studies were taken into account, and the appropriate assessment factors were used to define a final Predicted No-Effect Concentration (PNEC) value of 1100 µg/litre.

Monitoring measurements were taken in the UK (wide range of river estuaries), the Netherlands (North Sea coasts and open ocean, Rhine estuary, various rivers), France (Seine estuary) and Germany (Elbe and Weser estuaries, Rhine).

The most recent data (1991-95) support a typical PEC of 0.5 µg EDC/l water and a worst case PEC of 6.4 µg/l water. Data on persistence of EDC show a half-life in water of a few hours or days, and negligible bioaccumulation in aquatic organisms. EDC is not a substance which should be considered as being persistent, toxic and liable to bioaccumulate (PTB) in the environment.

Conclusion

When the environmental concentration of EDC in rivers and coastal waters/estuaries is compared with the predicted no-effect level to give the PEC/PNEC ratio, there is a safety margin of 170-2200 between actual exposure and the level at which no effect on the environment would be expected. This calculation takes no account of any further dilution within the sea, which would increase these safety margins.

Current use of 1,2-dichloroethane does not, therefore, represent a risk to the marine environment.

Type of water

Predicted environmental concentration (PEC)

PEC/Probable No-Effect Concentration (PNEC)

Coastal waters/estuaries
  • Worst case
  • Typical water


6.4 µg/l
0.5 µg/l

 

0.0058
0.00045

River waters
  • Worst case
  • Typical water

 

5 µg/l
0.5 µg/l

 

0.0045
0.00045

North Sea monitoring data on 1,2-dichloroethane

North Sea monitoring data on 1,2-dichloroethane

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