The vanishing act of vanishing spray

The 2014 FIFA World Cup has thrown a curious case of using vanishing spray by referees. The vanishing spray works in the following way :
The spray is basically a foam which is a substance that is formed by trapping many gaseous bubbles in a liquid or solid.

• Gas : propellant
• Liquid : water
• Foaming emulsifier keeps these two substances together. The gaseous propellant evaporates so that the foam vanishes to leave only water and other solutions.

Composition of the spray  (Source)

• Foaming emulsifier : polyoxyethylenated sorbitan monolaurate (polysorbate 20)
• Propellant : butane-isobutane-propane
• Cation chelating agent : tetrasodium EDTA 
• Preservative : diazolidinyl urea, propylene glycol, and butylcarbamate
• Water : distilled water, in a percentage from 80.00% to 95.00%