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| Chemical category | Application in hydraulic fracturing | Example compounds |
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| Proppants | Hold fissures open and allow gas to flow out of the formation | Sand, sintered bauxite, zirconium oxide, ceramic beads, and graphite |
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| Gellants | Increase viscosity and suspend sand during proppant transport | Propylene glycol, guar gum, ethylene glycol, and petroleum distillate |
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| Foamers | Increase carrying capacity while transporting proppants and decrease overall volume of fluid needed | 2-Butoxyethanol, diethylene glycol |
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| Cross-linkers | Thicken fluids to increase viscosity and proppant transport into fractures | Potassium hydroxide, ethylene glycol, borate salts, and petroleum distillates |
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| Breakers | Reduce the viscosity of the fluid so proppant will flow into fractures; added near the end of hydraulic fracturing to enhance flowback | Ammonium persulfate, magnesium peroxide |
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| Acids | Clean up cement and drilling mud before fracturing fluid is injected and clear the path through the formation. Used later to dissolve minerals and clays to reduce clogging, allowing gas to flow to the surface | Hydrochloric acid |
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| pH control | Maintains pH at various stages to ensure maximum effectiveness of various additives | Sodium hydroxide, acetic acid |
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| Biocides | Kill bacteria that produce gases (particularly H2S) which could contaminate methane gas, corrode pipes and fittings, and break down gellants | Glutaraldehyde, 2-bromo-2-nitro-1,2-propanediol |
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| Corrosion inhibitors | Reduce damage to steel from acidic HF fluids | Ethoxylated octylphenol and nonylphenol, isopropanol |
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| Scale inhibitors | Prevent buildup of mineral scale that can block fluid and gas passage through the pipes. Prevent steel materials from being damaged by acidic fracking fluids | Acrylamide, sodium polycarboxylate, methanol, and ammonium bisulfate |
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| Iron control | Prevents carbonate and sulfate compounds from precipitating to form plugs in shale formation | Ammonium chloride, ethylene glycol, and polyacrylate |
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| Clay stabilizers | Block clays from swelling to block the open channels created in the mining operation | Tetramethyl ammonium chloride, sodium chloride |
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| Defoamers | Reduce foaming after it is no longer needed; lowers surface tension; and allows trapped gas to escape | 2-Ethylhexanol, oleic acid, and oxalic acid |
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| Friction reducers | To make water slick and minimize the friction created under high pressure and to increase the rate and efficiency of moving the HF fluid | Acrylamide, ethylene glycol, petroleum distillate, methanol, sodium acrylate-acrylamide copolymer, polyacrylamide (PAM), and petroleum distillates |
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| Surfactants | Reduce surface tension and improve fluid passage through pipes in either direction | Methanol, ethanol, isopropanol, naphthalene, 1,2,4-trimethylbenzene, and 2-butoxyethanol |
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