Mystery chemicals

A look at the chemicals used in the fraccing process

A surprisingly controversial aspect of the hydraulic fraccing process is the nature of the chemicals used. Not the quantities of chemicals used or the risks associated with the chemicals but the actual identity.

Many people objecting to the use of coal seam gas state that they are unable to determine which chemicals are used in fraccing and are therefore unable to predict what the human and environmental health impacts might be. For instance, the National Toxics Network claims that only two of the  23 most commonly used chemicals used in fraccing have been assessed by the national regulator. Statements such as these certainly give the impression that mining companies are working in secret and releasing any number of mysterious chemicals into our water supply. The problem is, I don’t believe it’s the truth.

In Queensland, coal seam gas operators are required to undertake a risk assessment for all fraccing activities. This includes an assessment (and statement) of all chemicals used. I’m not sure whether these risk assessments are ever made public but they are at least made available to the government regulators. That is not what I would call ‘secret’.

The Queensland government has released a fact sheet, specifying the materials used in fraccing fluid. In general, the fluid is made up of 90% water, 9% sand (or similar inert material) and 1% ‘chemicals’. The chemicals used will vary a bit between companies, but generally consist of the following (as provided by QLD government):

  • Sodium hypochlorite;
  • Hydrochloric acid;
  • Surfactants;
  • Cellulose;
  • Acetic acid; and
  • Bactericides.

[Two of the above (surfactants and bactericides) might be better described as classes of chemicals, with the specific chemicals used varying from site to site.]

It is worth quickly noting what is not used in fraccing fluids in Queensland: BTEX chemicals (a group of volatile organic compounds – benzene, toluene, ethylbenzene and xylenes). Last year, the Queensland government introduced new regulations, banning the use of BTEX chemicals in the fraccing process. These chemicals have been identified as potential carcinogens and are pretty undesirable in our drinking water supply. I plan to discuss BTEX chemicals in more detail in later blog posts.

Next up: how are risks described?


One response

  1. Whilst doing your background research you may wish to look at FracFocus, the hydraulic fracturing chemical registry website.

    Also grab an electronic copy of “Composition and Properties of Drilling and Completion Fluids” from Amazon.

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