Metal-coated balloons, or mylars, can cause power outages and pose a public safety threat.

The metallic coating can conduct electricity, and can cause a short circuit or power surge when in contact with power lines. This can lead to large­scale power outages, melting of electrical wires, and fires, leading to possible injuries and property damage. Helium-filled balloons that float away can
drift for days and miles and can come down anywhere.