Converts gas, mat and reagent strings to defines

code/modules/events/atmos_leak.dm

@@ -19,11 +19,11 @@
 
 // Decide which area will be targeted!
 /datum/event/atmos_leak/setup()
-	var/gas_choices = list("carbon_dioxide", "nitrous_oxide") // Annoying
+	var/gas_choices = list(GAS_CO2, GAS_N2O) // Annoying
 	if(severity >= EVENT_LEVEL_MODERATE)
-		gas_choices += "phoron" // Dangerous
+		gas_choices += GAS_PHORON // Dangerous
 	// if(severity >= EVENT_LEVEL_MAJOR)
-	// 	gas_choices += "volatile_fuel" // Dangerous and no default atmos setup!
+	// 	gas_choices += GAS_VOLATILE_FUEL // Dangerous and no default atmos setup!
 	gas_type = pick(gas_choices)
 
 	var/list/area/grand_list_of_areas = get_station_areas(excluded)

code/modules/events/supply_demand_vr.dm

@@ -315,7 +315,7 @@
 	var/datum/gas_mixture/mixture = new
 	mixture.temperature = T20C
 	var/unpickedTypes = gas_data.gases.Copy()
-	unpickedTypes -= "volatile_fuel" // Don't do that one
+	unpickedTypes -= GAS_VOLATILE_FUEL // Don't do that one
 	for(var/i in 1 to differentTypes)
 		var/gasId = pick(unpickedTypes)
 		unpickedTypes -= gasId