diff --git a/code/modules/atmospherics/gasmixtures/gas_types.dm b/code/modules/atmospherics/gasmixtures/gas_types.dm
index 1542e081897..875fe2caef6 100644
--- a/code/modules/atmospherics/gasmixtures/gas_types.dm
+++ b/code/modules/atmospherics/gasmixtures/gas_types.dm
@@ -72,6 +72,7 @@ GLOBAL_LIST_INIT(nonreactive_gases, typecacheof(list(/datum/gas/oxygen, /datum/g
 	id = "co2"
 	specific_heat = 30
 	name = "Carbon Dioxide"
+	dangerous = TRUE
 	rarity = 700
 	purchaseable = TRUE
 	base_value = 0.2
@@ -171,6 +172,7 @@ GLOBAL_LIST_INIT(nonreactive_gases, typecacheof(list(/datum/gas/oxygen, /datum/g
 	id = "miasma"
 	specific_heat = 20
 	name = "Miasma"
+	dangerous = TRUE
 	gas_overlay = "miasma"
 	moles_visible = MOLES_GAS_VISIBLE * 60
 	rarity = 250
@@ -180,6 +182,7 @@ GLOBAL_LIST_INIT(nonreactive_gases, typecacheof(list(/datum/gas/oxygen, /datum/g
 	id = "freon"
 	specific_heat = 600
 	name = "Freon"
+	dangerous = TRUE
 	gas_overlay = "freon"
 	moles_visible = MOLES_GAS_VISIBLE *30
 	fusion_power = -5
diff --git a/code/modules/atmospherics/machinery/portable/canister.dm b/code/modules/atmospherics/machinery/portable/canister.dm
index beedded4b05..223dcc19af1 100644
--- a/code/modules/atmospherics/machinery/portable/canister.dm
+++ b/code/modules/atmospherics/machinery/portable/canister.dm
@@ -667,28 +667,35 @@ GLOBAL_LIST_INIT(gas_id_to_canister, init_gas_id_to_canister())
 			if(.)
 				release_pressure = clamp(round(pressure), can_min_release_pressure, can_max_release_pressure)
 				investigate_log("was set to [release_pressure] kPa by [key_name(usr)].", INVESTIGATE_ATMOS)
-		if("valve")
+		if("valve")		//logging for openning canisters
 			var/logmsg
+			var/admin_msg
+			var/danger = FALSE
+			var/n = 0
 			valve_open = !valve_open
 			if(valve_open)
 				SSair.start_processing_machine(src)
 				logmsg = "Valve was <b>opened</b> by [key_name(usr)], starting a transfer into \the [holding || "air"].<br>"
 				if(!holding)
-					var/list/danger = list()
+					var/list/gaseslog = list() //list for logging all gases in canister
 					for(var/id in air_contents.gases)
 						var/gas = air_contents.gases[id]
+						gaseslog[gas[GAS_META][META_GAS_NAME]] = gas[MOLES]	//adds gases to gaseslog
 						if(!gas[GAS_META][META_GAS_DANGER])
 							continue
 						if(gas[MOLES] > (gas[GAS_META][META_GAS_MOLES_VISIBLE] || MOLES_GAS_VISIBLE)) //if moles_visible is undefined, default to default visibility
-							danger[gas[GAS_META][META_GAS_NAME]] = gas[MOLES] //ex. "plasma" = 20
-
-					if(danger.len)
-						message_admins("[ADMIN_LOOKUPFLW(usr)] opened a canister that contains the following at [ADMIN_VERBOSEJMP(src)]:")
-						log_admin("[key_name(usr)] opened a canister that contains the following at [AREACOORD(src)]:")
-						for(var/name in danger)
-							var/msg = "[name]: [danger[name]] moles."
-							log_admin(msg)
-							message_admins(msg)
+							danger = TRUE //at least 1 danger gas
+					logmsg = "[key_name(usr)] <b>opened</b> a canister that contains the following:"
+					admin_msg = "[key_name(usr)] <b>opened</b> a canister that contains the following at [ADMIN_VERBOSEJMP(src)]:"
+					for(var/name in gaseslog)
+						n = n + 1
+						logmsg += "\n[name]: [gaseslog[name]] moles."
+						if(n <= 5) //the first five gases added
+							admin_msg += "\n[name]: [gaseslog[name]] moles."
+						if(n == 5 && gaseslog.len > 5) //message added if more than 5 gases
+							admin_msg += "\nToo many gases to log. Check investigate log."
+					if(danger) //sent to admin's chat if contains dangerous gases
+						message_admins(admin_msg)
 			else
 				logmsg = "Valve was <b>closed</b> by [key_name(usr)], stopping the transfer into \the [holding || "air"].<br>"
 			investigate_log(logmsg, INVESTIGATE_ATMOS)