Glendale City Council this week passed an ordinance banning the sale of mylar balloons filled with helium or other lighter-than-air gases within city limits.

According to the Glendale Water and Power utility website, helium Mylar balloons cause several power outages in the city each year. 

Mylar, a crinkly, metallic polyester film, is highly conductive. If a balloon is released into the sky and gets tangled in a high-voltage power line, the material can cause a short circuit.

The ordinance, which was passed Tuesday and will take effect Nov. 30, still allows the sale of mylar balloons filled with air. Such balloons do not float and thus do not present a threat to power lines.

GWP General Manager Steve Zurn said in a statement the ordinance will help reduce outages and damages to the city’s utility system.

“We look forward to new developments in the balloon industry that include non-conductive balloons that will not cause outages,” he added.

Glendale businesses that sell mylar balloons inflated with helium or other gases after the ordinance goes into effect will be subject to administrative citations, fees and, potentially, the filing of a misdemeanor charge.