diff --git a/homeassistant/components/nam/icons.json b/homeassistant/components/nam/icons.json
index 5e55bf145e5..594fd5fb5b7 100644
--- a/homeassistant/components/nam/icons.json
+++ b/homeassistant/components/nam/icons.json
@@ -18,9 +18,6 @@
       },
       "sps30_caqi_level": {
         "default": "mdi:air-filter"
-      },
-      "sps30_pm4": {
-        "default": "mdi:molecule"
       }
     }
   }
diff --git a/homeassistant/components/nam/sensor.py b/homeassistant/components/nam/sensor.py
index 45cfd313e8f..a7e5eb71912 100644
--- a/homeassistant/components/nam/sensor.py
+++ b/homeassistant/components/nam/sensor.py
@@ -324,6 +324,7 @@ SENSORS: tuple[NAMSensorEntityDescription, ...] = (
         translation_key="sps30_pm4",
         suggested_display_precision=0,
         native_unit_of_measurement=CONCENTRATION_MICROGRAMS_PER_CUBIC_METER,
+        device_class=SensorDeviceClass.PM4,
         state_class=SensorStateClass.MEASUREMENT,
         value=lambda sensors: sensors.sps30_p4,
     ),
diff --git a/tests/components/nam/snapshots/test_sensor.ambr b/tests/components/nam/snapshots/test_sensor.ambr
index 3071752267e..7ad641306b5 100644
--- a/tests/components/nam/snapshots/test_sensor.ambr
+++ b/tests/components/nam/snapshots/test_sensor.ambr
@@ -1812,7 +1812,7 @@
         'suggested_display_precision': 0,
       }),
     }),
-    'original_device_class': None,
+    'original_device_class': <SensorDeviceClass.PM4: 'pm4'>,
     'original_icon': None,
     'original_name': 'SPS30 PM4',
     'platform': 'nam',
@@ -1827,6 +1827,7 @@
 # name: test_sensor[sensor.nettigo_air_monitor_sps30_pm4-state]
   StateSnapshot({
     'attributes': ReadOnlyDict({
+      'device_class': 'pm4',
       'friendly_name': 'Nettigo Air Monitor SPS30 PM4',
       'state_class': <SensorStateClass.MEASUREMENT: 'measurement'>,
       'unit_of_measurement': 'μg/m³',