Hydraulic fracturing in the United States with hydraulic fracturing activity versus those without, with each well addition increasing rates of accidents by 2% and risk of fatality by .6%. Rig-Up and Rig-Down are terms used to refer to the delivery, construction, dismantling and breakdown of equipment required throughout the hydraulic fracturing process. Incidents and fatalities during rig-up/rig-down operations may result if struck or crushed by the heavy equipment involved. Hazards during Mixing and Injection Workers may be exposed to dangerous chemicals while mixing and injecting fluids used in hydraulic fracturing. Potential chemicals include, hydrochloric and hydrofluoric acid, biocides, methanol, ethylene glycol, guar gum, polysaccharides and polyacrylamides,
Hydrochloric acid prepared by dissolving sal ammoniac in nitric acid, was described in the works of Pseudo-Geber, a 13th-century European alchemist. Other references suggest that the first mention of aqua regia is in Byzantine manuscripts dating to the end of the 13th century. Free hydrochloric acid was first formally described in the 16th century by Libavius, who prepared it by heating salt in clay crucibles. Other authors claim that pure hydrochloric acid was first discovered by the German Benedictine monk Basil Valentine in the 15th century, when he heated common salt and green vitriol, whereas others argue that there is no clear