Yes, but not all of them. The shiny, foil Mylar balloons never break down, only becoming smaller pieces of plastic. The standard latex balloon is biodegradable but takes several months to break down.

Foil balloons can conduct electricity when caught in power lines, causing power outages and damaging equipment, and should be weighted and deflated after events to prevent this issue.

Mylar balloons are made of foil-coated plastic and never break down. They can float for miles and conduct electricity. After the most recent mess in New Orleans, Entergy is on the offensive.

Mylar balloons — the shiny, helium-filled foil kind you see all over Instagram — caused 1,128 power outages in Southern California in 2018, nearly double the 656 recorded four years earlier.

A power outage caused by a Mylar balloon led to a near-citywide boil water advisory. Here's how Mylar party supplies have caused problems in New Orleans over the years.

Bay City Electric Light and Power (BCELP) department reported that a runaway mylar balloon caused a power outage in the South End of Bay City at approximately 7:09 p.m. on Sunday, May 23.

A boil water advisory is in effect for the East Bank of New Orleans and Algiers Point after a foil balloon hit a power line and briefly caused an outage at a water treatment plant.