Here are some of the common uses of red flammable stickers:

• On containers of flammable liquids, such as gasoline, paint thinner, and acetone.
• On gas cylinders containing flammable gases, such as propane and acetylene.
• On aerosol cans containing flammable propellants.
• On fireworks and other pyrotechnic devices.
• On equipment that generates heat, such as welding torches and ovens.

The specific requirements for red flammable stickers may vary depending on the jurisdiction. However, they are generally required by law for any substance that meets the definition of a flammable liquid or gas.