diff --git a/data/json/field_type.json b/data/json/field_type.json
index aff1a0b7087e7..d0f49acc82a27 100644
--- a/data/json/field_type.json
+++ b/data/json/field_type.json
@@ -248,9 +248,71 @@
     "type": "field_type",
     "legacy_enum_id": 13,
     "intensity_levels": [
-      { "name": "hazy cloud", "sym": "8", "dangerous": true, "translucency": 1 },
-      { "name": "toxic gas", "color": "light_green", "transparent": false, "translucency": 10 },
-      { "name": "thick toxic gas", "color": "green", "translucency": 0 }
+      {
+        "name": "hazy cloud",
+        "sym": "8",
+        "dangerous": true,
+        "translucency": 1,
+        "effects": [
+          {
+            "effect_id": "poison",
+            "body_part": "MOUTH",
+            "intensity": 2,
+            "min_duration": "2 minutes",
+            "max_duration": "2 minutes",
+            "immune_inside_vehicle": true,
+            "message": "You feel sick from inhaling the hazy cloud",
+            "message_type": "bad"
+          }
+        ]
+      },
+      {
+        "name": "toxic gas",
+        "color": "light_green",
+        "transparent": false,
+        "translucency": 10,
+        "effects": [
+          {
+            "effect_id": "poison",
+            "body_part": "MOUTH",
+            "intensity": 5,
+            "min_duration": "3 minutes",
+            "max_duration": "3 minutes",
+            "immune_inside_vehicle": true,
+            "message": "You feel sick from inhaling the toxic gas",
+            "message_type": "bad"
+          }
+        ]
+      },
+      {
+        "name": "thick toxic gas",
+        "color": "green",
+        "translucency": 0,
+        "effects": [
+          {
+            "effect_id": "poison",
+            "body_part": "MOUTH",
+            "intensity": 5,
+            "min_duration": "3 minutes",
+            "max_duration": "3 minutes",
+            "//": "won't be applied outside of vehicles, so it could apply harsher effect",
+            "immune_outside_vehicle": true,
+            "message": "You feel sick from inhaling the thick toxic gas",
+            "message_type": "bad"
+          },
+          {
+            "effect_id": "badpoison",
+            "body_part": "MOUTH",
+            "intensity": 5,
+            "min_duration": "3 minutes",
+            "max_duration": "3 minutes",
+            "//": "won't be applied inside of vehicles, so it could apply lesser effect",
+            "immune_inside_vehicle": true,
+            "message": "You feel sick from inhaling the thick toxic gas",
+            "message_type": "bad"
+          }
+        ]
+      }
     ],
     "decay_amount_factor": 5,
     "gas_absorption_factor": 15,
diff --git a/src/map_field.cpp b/src/map_field.cpp
index f244ce9349a6e..bd373fe44b101 100644
--- a/src/map_field.cpp
+++ b/src/map_field.cpp
@@ -1537,25 +1537,6 @@ void map::player_in_field( player &u )
                 u.add_env_effect( effect_blind, bp_eyes, 2, 2_turns );
             }
         }
-        if( ft == fd_toxic_gas ) {
-            // Toxic gas at low levels poisons you.
-            // Toxic gas at high levels will cause very nasty poison.
-            {
-                bool inhaled = false;
-                if( ( cur.get_field_intensity() == 2 && !inside ) ||
-                    ( cur.get_field_intensity() == 3 && inside ) ) {
-                    inhaled = u.add_env_effect( effect_poison, bp_mouth, 5, 3_minutes );
-                } else if( cur.get_field_intensity() == 3 && !inside ) {
-                    inhaled = u.add_env_effect( effect_badpoison, bp_mouth, 5, 3_minutes );
-                } else if( cur.get_field_intensity() == 1 && !inside ) {
-                    inhaled = u.add_env_effect( effect_poison, bp_mouth, 2, 2_minutes );
-                }
-                if( inhaled ) {
-                    // Player does not know how the npc feels, so no message.
-                    u.add_msg_if_player( m_bad, _( "You feel sick from inhaling the %s" ), cur.name() );
-                }
-            }
-        }
 
         if( cur.extra_radiation_min() > 0 ) {
             // Get irradiated by the nuclear fallout.