The differences between additives for hydraulic fracturing in different countries are the type of chemicals used (hazardous, non-hazardous), the disclosure of chemicals and the composition of fracturing fluid. In 2010, Halliburton announced the creation of food additive based hydraulic fracturing fluid in response to calls for transparency and demand for a "more environmentally friendly" unconventional hydrocarbon production.
In Europe, Poland, Norway and Germany have the largest reserves of shale gas, and drillings are underway.
In the United Kingdom, the environmental regulator permits only chemical additives which are classed as non hazardous to groundwater for fracturing fluids. All chemicals used in fracturing fluids used must be declared publicly, while the composition must be disclosed if the regulator demands it. The permitted additives for hydraulic fracturing fluid include polycrylamide, hydrochloric acid and a biocide.
In the US, about 750 compounds have been listed as additives for hydraulic fracturing, also known as ingredients of pressurized fracking fluid, in an industry report to the US Congress in 2011 after originally being kept secret for "commercial reasons". The following is a partial list of the chemical constituents in additives that are used or have been used in fracturing operations, as based on the report of the New York State Department of Environmental Conservation, some are known to be carcinogenic.