Crossword Genius

Substance formerly used to extinguish fires involving electronic equipment (5)

Ross

I believe the answer is:

halon

(Other definitions for halon that I've seen before include "fire extinguisher" , "Gas in fire extinguishers" .)

I've seen this clue in The Sunday Times and The Times.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.