Which gas is most commonly used to propel fumigants?

• A. Nitrogen gas
• B. Helium gas
• C. Neon gas
• D. Chlorine gas

Answer: (A)

Propellant gas for fumigants needs to be inert, nonflammable, and inexpensive so it can carry and spread the fumigant without reacting with it or creating safety hazards. Nitrogen gas fits these needs perfectly. It makes up most of the air we breathe, is cheap to obtain, and won't react with common fumigants or the materials involved in fumigation. Using nitrogen helps push the fumigant through cracks and spaces while keeping the environment safe by not supporting combustion or causing chemical reactions. Other gases like helium are inert but expensive for large-scale use; neon is also costly with little practical benefit; chlorine gas is reactive and toxic, which would create dangerous conditions. That combination of safety, cost, and practicality is why nitrogen is the gas most commonly used to propel fumigants.