Vox oxygen toxicity, vox breath mask, nitrogen tank for spawning.

code/game/objects/items/weapons/tanks/tank_types.dm

@@ -162,3 +162,28 @@
 	name = "double emergency oxygen tank"
 	icon_state = "emergency_double"
 	volume = 10
+
+/*
+ * Nitrogen
+ */
+/obj/item/weapon/tank/nitrogen
+	name = "nitrogen tank"
+	desc = "A tank of nitrogen."
+	icon_state = "oxygen_fr"
+	distribute_pressure = ONE_ATMOSPHERE*O2STANDARD
+
+
+/obj/item/weapon/tank/nitrogen/New()
+	..()
+
+	src.air_contents.nitrogen = (3*ONE_ATMOSPHERE)*70/(R_IDEAL_GAS_EQUATION*T20C)
+	//
+	src.air_contents.update_values()
+	return
+
+/obj/item/weapon/tank/nitrogen/examine()
+	set src in usr
+	..()
+	if(air_contents.nitrogen < 10)
+		usr << text("\red <B>The meter on the [src.name] indicates you are almost out of air!</B>")
+		playsound(usr, 'sound/effects/alert.ogg', 50, 1)

code/modules/clothing/masks/breath.dm

@@ -35,4 +35,26 @@
 	name = "medical mask"
 	icon_state = "medical"
 	item_state = "medical"
-	permeability_coefficient = 0.01
+	permeability_coefficient = 0.01
+
+/obj/item/clothing/mask/breath/vox
+	desc = "A weirdly-shaped breath mask."
+	name = "vox breath mask"
+	icon_state = "voxmask"
+	item_state = "voxmask"
+	permeability_coefficient = 0.01
+
+	toggle()
+		set category = "Object"
+		set name = "Adjust mask"
+		set src in usr
+
+		usr << "You can't really adjust this mask - it's moulded to your beak!"
+
+/obj/item/clothing/mask/breath/vox/mob_can_equip(M as mob, slot)
+	var/mob/living/carbon/human/V = M
+	if(V.dna.mutantrace != "vox")
+		V << "<span class='warning'>This clearly isn't designed for your species!</span>"
+		return 0
+
+	return ..()

code/modules/mob/living/carbon/human/life.dm

@@ -394,6 +394,7 @@
 		var/oxygen_used = 0
 		var/nitrogen_used = 0
 		var/breath_pressure = (breath.total_moles()*R_IDEAL_GAS_EQUATION*breath.temperature)/BREATH_VOLUME
+		var/safe_oxygen_max = 1 // For vox.
 
 		//Partial pressure of the O2 in our breath
 		var/O2_pp = (breath.oxygen/breath.total_moles())*breath_pressure
@@ -436,6 +437,12 @@
 				adjustOxyLoss(HUMAN_MAX_OXYLOSS)
 				failed_last_breath = 1
 			oxygen_alert = max(oxygen_alert, 1)
+
+			if(O2_pp > safe_oxygen_max) //Oxygen is toxic to vox.
+				var/ratio = (breath.oxygen/safe_oxygen_max) * 10
+				adjustToxLoss(Clamp(ratio, MIN_PLASMA_DAMAGE, MAX_PLASMA_DAMAGE))
+				toxins_alert = max(toxins_alert, 1)
+
 		else								// We're in safe limits
 			failed_last_breath = 0
 			adjustOxyLoss(-5)