Oil spill dispersants: boon or bane?

Environ Sci Technol. 2015 Jun 2;49(11):6376-84. doi: 10.1021/acs.est.5b00961. Epub 2015 May 15.


Dispersants provide a reliable large-scale response to catastrophic oil spills that can be used when the preferable option of recapturing the oil cannot be achieved. By allowing even mild wave action to disperse floating oil into tiny droplets (<70 μm) in the water column, seabirds, reptiles, and mammals are protected from lethal oiling at the surface, and microbial biodegradation is dramatically increased. Recent work has clarified how dramatic this increase is likely to be: beached oil has an environmental residence of years, whereas dispersed oil has a half-life of weeks. Oil spill response operations endorse the concept of net environmental benefit, that any environmental costs imposed by a response technique must be outweighed by the likely benefits. This critical review discusses the potential environmental debits and credits from dispersant use and concludes that, in most cases, the potential environmental costs of adding these chemicals to a polluted area are likely outweighed by the much shorter residence time, and hence integrated environmental impact, of the spilled oil in the environment.

Publication types

  • Review

MeSH terms

  • Animals
  • Biodegradation, Environmental
  • Environmental Monitoring
  • Half-Life
  • Hazardous Substances / analysis*
  • Particle Size
  • Petroleum / analysis*
  • Petroleum Pollution / analysis*
  • Petroleum Pollution / prevention & control
  • Water Pollutants, Chemical / analysis*


  • Hazardous Substances
  • Petroleum
  • Water Pollutants, Chemical