LewisGoetz Blog Flange Leakage: Refining Hazards in HF Units

Hazardous Nature of Hydrogen Fluoride Anhydrous Hydrogen Fluoride (AHF) is used as a catalyst in the reaction that combines C3 and C4 olefins and isobutane to produce alkylates, an important component of gasoline. AHF readily reacts with any available moisture to create the corrosive and toxic Hydrofluoric Acid.So hazardous is this material to humans that OSHA lists the Permissible Exposure Limit (PEL) to 3-ppm averaged over an 8-hour shift, while the National Institute for Occupational Safety and Health (NIOSH) lists the IDLH (Immediately Dangerous to Life or Health) concentration at 30-ppm. In and of itself, this hazard level arguably makes HF Acid Alkylation Units the single most dangerous sealing application in modern refining.