What is Fluorine?

Fluorine (F) is a pale yellow-green, poisonous halogen gas with the atomic number 9. It is the most chemically reactive and electronegative of all elements, forming compounds with almost every other element—including the noble gases krypton, xenon, and radon.

Fluorine is so reactive that it can ignite glass, metals, and even water, producing a bright flame when released in a jet. In aqueous solution, it is commonly present as the fluoride ion (F⁻), typically bound to positively charged counterparts.

Fluorine does not occur naturally in its elemental state. Instead, it is found as fluoride compounds in minerals and environmental media.

What is Fluorine used for?

Fluorine and its compounds have many industrial applications, including:

• Metals and manufacturing: aluminium refining, smelting fluxes, ceramics, dyes, and glass/enamel etching.
• Semiconductors: atomic and molecular fluorine are used for plasma etching in microelectronics, flat-panel displays, and MEMS fabrication.
• Plastics and refrigerants: production of low-friction plastics (e.g., Teflon) and halons such as Freon.
• Petrochemical industry: processing and refining.
• Nuclear industry: in the production of uranium compounds.
• Agricultural chemicals: as components in pesticides and fumigants.

In the Environment

• Air to water/soil transfer: Fluorine released into air can settle in water or soils, where it strongly binds to soil particles.
• Persistence: Fluorine cannot be destroyed—only change form.
• Plant uptake: Sensitive plants (e.g., corn and apricots) show leaf damage, stunted growth, and reduced yields even at low fluorine concentrations.
• Animal uptake: Animals consuming contaminated plants accumulate fluorine in their bones and teeth, leading to dental decay, bone degradation, impaired claw development, reduced food absorption, and low birth weights.

Sources and Routes of Exposure

Sources of Exposure

• General population: exposure may occur via contaminated air, food, drinking water, or soil.
• Drinking water: communities with fluoridated water or naturally high levels of fluoride may experience higher exposure.
• Occupational/industrial: people working in or living near industries where fluorine-containing substances are manufactured or used are at greater risk of exposure.

Routes of Exposure

The main routes of fluorine exposure are:

• Inhalation of contaminated air
• Skin contact with liquid or gaseous fluorine
• Eye contact with gas or splashes of liquid fluorine

Health Effects

Fluorine is an extremely strong irritant to all tissues it contacts. The severity of injury ranges from mild irritation to caustic burns, depending on concentration and duration of exposure.

• Respiratory system: A severe irritant of the lungs and mucous membranes. Inhalation may cause respiratory tract irritation that can progress to pulmonary oedema.
• Skin: Fluorine reacts violently with moisture on the skin, causing thermal burns. Direct contact with liquid fluorine may result in frostbite.
• Eyes: Highly irritating, capable of causing severe damage to ocular tissues.
• Systemic effects: Tissue injury is primarily due to the formation of hydrofluoric acid when fluorine reacts with moisture in the body.

The lungs are considered the most vulnerable organ following fluorine exposure.

Safety

First Aid Measures

• Inhalation: Move the victim to an uncontaminated area while wearing a self-contained breathing apparatus (SCBA). Keep warm and at rest. If breathing has stopped, apply artificial respiration. Call a doctor immediately.
• Skin contact: Remove contaminated clothing and drench affected areas with water for at least 15 minutes. While wearing rubber gloves, rub 2.5% calcium gluconate gel continuously into the skin for 1.5 hours or until medical help is available. Obtain urgent medical assistance.
• Eye contact: Flush eyes with water for at least 15 minutes. If available, irrigate intermittently for 20 minutes with 1% aqueous calcium gluconate solution. Seek immediate medical attention.
• Ingestion: Not considered a likely exposure route.
• Delayed effects possible: prolonged exposure to low concentrations may cause pulmonary oedema. Severe exposure can cause chemical burns to the skin and cornea. A corticosteroid spray is recommended after inhalation exposure.

Fire Information

• Extinguishing media: Dry powder or carbon dioxide only.
• Do not use water — fluorine reacts violently with it.
• Exposure to fire may cause containers to rupture or explode.

Exposure Controls and Personal Protection

Engineering Controls

• Conduct a documented risk assessment for all work areas.
• Handle fluorine only in closed systems under strictly controlled conditions.
• Keep concentrations well below occupational exposure limits.
• Use a work permit system for maintenance activities.
• Employ leak-tight connections (e.g., welded pipes) and regularly check pressurised systems for leaks.
• Provide adequate local or general ventilation.
• Install gas detectors to monitor toxic or oxidising gas releases.

Personal Protective Equipment (PPE)

• Eye/face protection: Chemical goggles and face shield; EN 166-compliant protection; full-face mask recommended.
• Hand protection: Chemically resistant gloves (neoprene, EN 374 standard) and safety shoes.
• Body protection: Chemically resistant protective clothing suitable for the task; keep emergency protective clothing readily available.
• Respiratory protection: SCBA must be available for emergencies and used at high concentrations. Selection of RPD/RPE should be based on exposure levels, product hazards, and equipment safe-working limits.

Regulation

United States

OSHA: The United States Occupational Safety & Health Administration has set the following Permissible Exposure Limit (PEL) for fluorine:

• General Industry: 29 CFR 1910.1000 Table Z-1 - 0.1 ppm, 0.2 mg/m³ TWA 
• Construction Industry: 29 CFR 1926.55 Appendix A - 0.1 ppm, 0.2 mg/m³ TWA 
• Maritime: 29 CFR 1915.1000 Table Z-Shipyards - 0.1 ppm, 0.2 mg/m³ TWA

ACGIH: The American Conference of Governmental Industrial Hygienists has set a Threshold Limit Value (TLV) for fluorine of 1 ppm, 1.6 mg/m³ TWA; 2 ppm, 3.1 mg/m³ STEL

NIOSH: The National Institute for Occupational Safety and Health has set a Recommended Exposure Limit (REL) for fluorine of 0.1 ppm, 0.2 mg/m³ TWA

Australia

Safe Work Australia: Safe Work Australia has set a Time Weighted Average (TWA) concentration for fluorine of 1 ppm, 1.6 mg/m³ for a 40-hour workweek.