Sulphuryl fluoride (SO₂F₂) is a colourless and odourless gas. It is non-flammable, non-corrosive, and does not react with materials to leave behind odours or residues.
This gas has a very low boiling point of -55.2°C and a high vapour pressure of 17.7 mm Hg at 25°C.
What is Sulphuryl Fluoride used for?
Sulphuryl fluoride was first registered as a pesticide in 1959. It is used to fumigate closed structures (like homes and warehouses) for pests such as:
Termites (drywood and Formosan)
Wood-infesting beetles
Bedbugs
Carpet beetles
Clothes moths
Cockroaches
Rodents
In 2005, the EPA approved its use on harvested and processed food (like coffee and cocoa beans) and for fumigating food processing facilities.
Sulphuryl fluoride is used to fumigate closed structures (like homes and warehouses) for Termites (drywood and Formosan).
In the Environment
Recent studies found sulphuryl fluoride has a much longer atmospheric lifetime than previously thought — 30 to 40 years instead of 5. It’s also a greenhouse gas, 4000–5000 times more powerful (per kg) than carbon dioxide at trapping heat.
However, the amount released into the atmosphere (2000 metric tons per year) is very small compared to CO₂ emissions (30 billion metric tons annually). The gas mainly breaks down by dissolving in ocean water and undergoing hydrolysis.
Routes of Exposure
People can be exposed to sulphuryl fluoride mainly by:
Inhaling the gas
Getting it in the eyes
Health Effects
Acute Effects
Short-term exposure to sulphuryl fluoride can cause:
Eye, nose, throat, and lung irritation
Shortness of breath
Numbness and weakness
Nausea and stomach pain
Slowed movements or speech
Central nervous system depression
Coughing, vomiting, restlessness
Muscle twitching, seizures
Pulmonary edoema (fluid in lungs)
Chronic Effects
Repeated high exposures may lead to:
Lung damage
Kidney damage
Mottled teeth
Fatalities have occurred when people entered buildings too soon after fumigation, before gas levels dropped to safe levels.
Reproductive and developmental Effects
Animal studies show
In pregnant rats and rabbits, no birth defects (teratogenic effects) were observed.
In rats, there were no signs of developmental or maternal toxicity.
In rabbits, high exposures caused:
Reduced foetal body weight
Shorter crown-rump length
These effects occurred at exposure levels that also caused reduced maternal weight gain.
Additional reproductive studies found that
At 20 and 150 ppm, lung and brain effects were seen in adult (parent) rats.
Pups exposed to the highest dose had reduced body weight.
In humans, there is no data from occupational, accidental, or clinical studies to determine whether sulphuryl fluoride causes reproductive or developmental effects.
Cancer Risk
There is no data showing sulphuryl fluoride causes cancer in humans from workplace or accidental exposure.
Safety
First Aid Measures
Eyes: Rinse with water for at least 5 minutes. Watch for frostbite. Seek medical help.
Skin: If clothing is wet with sulphuryl fluoride, apply water before removing it. After thawing, remove items and wash or shower thoroughly.
Ingestion: No significant effects expected.
Inhalation: Move to fresh air. Provide artificial respiration if needed. Call a doctor or go to a hospital.
Exposure Control & Personal Protection
Engineering Controls
Use local or general ventilation to keep air levels safe. Dangerous concentrations may build up in poorly ventilated spaces.
Personal Protective Equipment (PPE)
Respiratory Protection: Use NIOSH-approved positive-pressure supplied-air respirators. For emergencies or confined spaces, use a self-contained breathing apparatus (SCBA).
Skin Protection: Normally not required. Avoid skin contact with liquid sulfuryl fluoride, as it may cause frostbite. Do not wear gloves or rubber boots that could trap the liquid.
Eye Protection: Wear chemical safety goggles.
Regulation
United States
OSHA: Airborne permissible exposure limit (PEL) is 5ppm averaged over 8hour workshift.
NIOSH: Airborne exposure limit is 5ppm averaged over 10-hour workshift and 10ppm, not to be exceeded during any 15-minute work period.
ACGIH: Airborne exposure limit is 5ppm averaged over 8 hours workshift and 10ppm short-term exposure limit (STEL)
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