Final answer:
True, outdoor refueling requires maintaining a 20-foot distance from an open flame to prevent ignition of flammable vapors and ensure safety.
Step-by-step explanation:
The statement is true; when outdoor refueling, it is a standard safety regulation to maintain a distance of at least 20 feet from any open flame or ignition source. This safety precaution is put in place to prevent the ignition of flammable vapors, which can occur if fuel comes into contact with an open flame. It is crucial to follow all safety guidelines during fuel handling to minimize the risk of fires or explosions, which can result in property damage, injury, or loss of life.