- Helium balloons deflate over time as they lose gas through the walls and imperfections in the sealed neck of the balloon.
- Latex balloons are more porous and allow the helium to leak out more rapidly. Unless coated with a special sealant, latex balloons will deflate in 8 to 12 hours.
- Mylar balloons can hold helium for much longer, usually several days. The helium will still escape the Mylar balloon through microscopic leaks in the neck of the balloon.
















