Guar gum needs to be thin enough to make it easier to pump. Then as it flows down the pipe, the fluid needs to gel up to support the proppant and flush it deep into the fractures. After that process, the gel has to break down so we can flow back and recover the fracking fluid, but leave the proppant behind. This requires a chemical process which produces then breaks the gel cross-linking at a predictable rate. Guar+boron+proprietary chemicals can accomplish both of these goals at once. Guar gum retards ice crystal growth nonspecifically by slowing mass transfer across the solid/liquid interface.
Guar gum also known to cause small sores or lesions as well as chronic diarrhea (IBS). Manufacturers and suppliers will sometimes substitute guar Gum, xanthan gum and cellulose gum in formulations, without changing product labels. Often, blends of all these ingredients are sold as cellulose gum. If allergic to guar gum, the most common foods to suspect contamination from are frozen dairy/ice treats, soft cheeses (cream cheese, ricotta), salad dressing and baked goods. In July 2007, the European Commission issued a health warning to its member states after high levels of dioxins were detected in a food additive - guar gum -