Okay, so I figured out what the three numbers are:
Code:
player:AddEffect( EF.kGas, effect duration, icon duration, speed )
Testing what speed does in this context (if anything). Maybe it's the fade-in time? But probably it's nothing.
EDIT: Speed doesn't look like it does anything. Each tick does 1 damage. Probably going to have to mess with the player_ongas() function to get it to work how you want it.