If any freezing agent leaks/escapes from the bottom of the cap when 'charging', then it’s likely that the cap is being depressed for too long.
Any such escape of the freezing agent will very quickly vaporise (possibly appearing as a mist).
Take care to avoid contact with skin, clothing, fabrics, jewellery and metal or polished surfaces as it may cause permanent damage.
When 'charging' the foam applicator it is important to stand the can on a suitable surface, so that the hands only come into contact with the dome-shaped safety cap as it is depressed.