The short answer to that only Cuadrilla Resources, and perhaps its contractors, know and they have not been particularly forthcoming on this question, while simultaneously proclaiming that they are being extremely open on the issue. Some information is available on Cuadrilla’s website but that does not seem to be entirely consistent with what the have told the Environment Agency or are telling the press. Below is a table listing a small number of chemicals that it appears they might be using:
|Hydrochloric acid||Acid||N/A||Extremely corrosive. Inhalation of vapour can cause serious injury. Ingestion may be fatal. Liquid can cause severe damage to skin and eyes.|
|FR-40||Friction reducer||Cocktail of chemicals including Polyacrylamide||Causes mild to moderate irritation. Prolonged skin contact may defat the skin and product dermatitis.|
|Ucarcide||Biocide||Bacteria-killing pesticide whose active substance is Glutaraldehyde||Corrosive. Causes irreversible eye damage. Causes skin burns, Harmful if inhaled. May be fatal if swallowed. Harmful if absorbed through skin. Aspiration may cause lung damage.|
|StimLube W||Friction reducer||Hydrotreated Light Distillate||Do not ingest. Ingestion of small quantities is usually nonfatal unless aspiration occurs. Aspiration may lead to chemical pneumonitis, which is characterized by pulmonary edema and hemorrhage and may be fatal.|
The toxicity information is drawn from Material Safety Data Sheets for the products. It can be seen that even this limited list don’t sound particularly nice and and certainly not like the foodstuffs that Cuadrilla has been claiming. One could imagine that the 33,000 litres of these chemicals needed to perform a single frack of a well (assuming 3.5 million US gallons of fluid is to frack a horizontal well and 0.25 percent of that is chemicals) is not going to be very good for anything wherever it ends up.
However in actual gas production in the United States using hydraulic fracturing, rather than the small scale testing that Cuadrilla is undertaking at the moment, hundreds of chemicals are used (“companies used more than 2,500 hydraulic fracturing products containing 750 different chemicals and other components”), including breakers, corrosion inhibitors, crosslinkers, gels, oxygen scavengers, pH adjusting agents, scale inhibitors and surfactants. It seems a little hard to believe that either the companies in the US are doing all this just for fun or that the laws of physics are different in the UK so they aren’t needed here.
This leaves us with two possibilities. Either Cuadrilla is lying about the chemicals that it is using at the moment or given that it is only testing rather than actually trying to produce gas in large amounts, they may not need to use all those chemicals at the moment. It probably doesn’t actually matter in the big picture which of these two options is the correct one since in the long run Cuadrilla, or whoever takes over from them, would end up using all those chemicals in very large quantities for actual gas production. Of course if you happen to be living next to one of the test wells that Cuadrilla is fracking then exactly what chemicals they are using now is more of a concern.
Note that fracking chemicals are just a part of the story in terms of water contamination with materials leached out of the shale rock itself also of great concern.