Introduction to Hydrogen Fluoride (HF)

Hydrogen Fluoride (HF) is a colorless gas with a strong, irritating odor. Hydrogen Fluoride is the principal industrial source of fluorine and is primarily used as an industrial raw material. It is used to make refrigerants, herbicides, pharmaceuticals, high-octane gasoline, plastics, and fluorescent light bulbs. Unlike the other hydrogen halides, Hydrogen Fluoride is lighter than air and diffuses relatively quickly through porous substances.

Upon contact with moisture and tissue, Hydrogen Fluoride immediately converts to the highly corrosive and toxic hydrofluoric acid. However, it is still very toxic in its gaseous state. Personnel working with Hydrogen Fluoride can be exposed in numerous ways, primarily through gas container leaks. This release could occur at an industrial site or even at a retail location. It is essential for facilities that work with this toxic gas to monitor for hazardous levels at all times.

Health Hazards

When present in high concentrations, Hydrogen Fluoride may produce these symptoms:

  • Eye, nose, respiratory irritation
  • Visual defects, blindness
  • Lung disease
  • Irregular heartbeat
  • Pulmonary edema (excess fluid in lung tissue)

Exposure Limits

When researching HF gas detection solutions, facility managers should be aware of the following HF exposure limits:

Exposure Limits Agency
3 ppm TWA OSHA PEL (General Industry)
3 ppm TWA OSHA PEL (Construction Industry)
3 ppm TWA OSHA PEL (Maritime)
3 ppm ceiling ACGIH TLV
3 ppm TWA, 6 ppm ceiling NIOSH REL

Technology for HF Gas Detection

Electrochemical Sensors

Electrochemical sensors are fuel cell-like devices consisting of an anode, cathode, and electrolyte. The components of the cell are selected so that a subject gas, allowed to diffuse into the cell, will cause a chemical reaction and generate a current. The cells are diffusion-limited, meaning that the rate of the gas entering the cell is solely dependent on the gas concentration. The current generated is proportional to the rate of consumption of the subject gas in the cell.

Learn more about the advantages of using Sierra Monitor's electrochemical gas sensor modules »