Most commonly used as a lightning bolt for stormy weather, this symbol is intended to be a warning for high voltage
Apple also uses this symbol for its high speed Thunderbolt port.
High Voltage was approved as part of Unicode 4.0 in 2003 under the name “High Voltage Sign” and added to Emoji 1.0 in 2015.
⚡ Lightning Bolt
⚡ High Voltage
⚡ High Voltage Sign