Volatile organic compounds value

The Volatile organic compounds value condition passes when a VOC sensor’s reading meets a specific level. VOCs are invisible gases released by paints, cleaning supplies, new furniture, and even scented candles. You often notice them as that “new car” or “fresh paint” smell, and at higher concentrations they affect comfort and health. This condition lets your automation respond proportionally, turning on the ventilation fan only when VOC readings are genuinely elevated and leaving it off during a normal day so you save energy.

Using this condition from the user interface

If you prefer building automations visually, Home Assistant walks you through this condition step by step. You pick what to check, tweak a few options, and save. No YAML knowledge required.

To use this condition in an automation:

1. Go to Settings > Automations & scenes.
2. Open an existing automation, or select Create automation > Create new automation.
3. In the And if section, select Add condition.
4. Select what you want to check. Under By target (see Targets), pick the area your air quality sensor is in (like your living room or bedroom). You can also select a floor, a device, a specific entity, or a label.
5. From the conditions shown for that target, select Volatile organic compounds value.
6. Under Threshold type, set the VOC level the condition checks against.
7. Under Condition passes if (see Behavior), pick Any or All.
8. Select Save.

Options in the UI

Using this condition in YAML

If you work directly in YAML, or you want to know exactly what Home Assistant does under the hood, this section has the technical reference. It lists the field names you use in YAML, their types, and which ones are required.

In YAML, refer to this condition as air_quality.is_voc_value. A basic example looks like this:

condition: air_quality.is_voc_value
target:
  entity_id: sensor.living_room_voc
options:
  threshold: 300
  behavior: any

This passes when the living room VOC sensor reads at or above 300 µg/m³.

Options in YAML

YAML sometimes provides additional options for more complex use cases that are not available through the UI.

Targets

This condition supports targets. A target tells Home Assistant what the condition should check. You can point it at a single entityAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more], a device, an area, a floor, or a label, and Home Assistant evaluates every matching air_quality entity behind that target.

• Entity: one specific air_quality entity, such as air_quality.living_room.
• Device: every air_quality entity that belongs to a device.
• Area: every air_quality entity in a room or area.
• Floor: every air_quality entity on a floor.
• Label: every air_quality entity that shares a label.

You can also mix target types in one condition. For example, combine a specific entity with an area to check both at once.

Behavior with multiple targets

When you target more than one entity (or select an area, floor, or label that contains several), the Condition passes if option controls how the results combine:

• Any (default): the condition passes if at least one of the targeted entities matches. For example, if you check three smoke sensors and only one of them detects smoke, the condition still passes. This is useful for questions like “is there smoke anywhere in the house?”
• All: the condition passes only when every targeted entity matches. For example, if you check the same three smoke sensors, the condition passes only once all three report cleared. This is useful for “is the entire house safe now?” checks, so your automation does not send an all-clear while one room still has a reading.

Good to know

• Sensors that are unavailable (unavailable) or have an unknown state (unknown) are skipped for Any and fail for All.
• Some sensors report VOCs as a ratio instead of an absolute concentration. For those sensors, use Volatile organic compounds ratio value.

Try it yourself

Ready to test this? Go to Settings > Automations & scenes, open an automation, and add this condition. Trigger the automation with and without the condition met, and watch whether it continues or stops.

More examples

Real scenarios where this condition gates an automation. Copy any example and adapt it to your setup.

Automation: start the air purifier when you wake up only if VOC levels are high

Overnight, off-gassing from furniture, carpets, and cleaning products pushes VOC levels up in a closed room. This automation triggers at wake-up time and checks the living room VOC reading. If the level is at or above 300 μg/m3, the air purifier turns on to clear the air before you start your day. On mornings when the air is already fresh, the purifier stays off and you save energy.

• Trigger: Time: 07:00
• Condition: Air Quality: Volatile organic compounds value
• Target: Living room VOC sensor
• Threshold type: 300
• Condition passes if: Any
• Action: Fan: Turn on (air purifier)

alias: "Morning purifier if VOCs are high"
triggers:
  - trigger: time
    at: "07:00:00"
conditions:
  - condition: air_quality.is_voc_value
    target:
      entity_id: sensor.living_room_voc
    options:
      threshold: 300
      behavior: any
actions:
  - action: fan.turn_on
    target:
      entity_id: fan.living_room_purifier

Still stuck?

The Home Assistant community is quick to help: join Discord for real-time chat, post on the community forum with the condition you’re using and what you expected to happen, or share on our subreddit /r/homeassistant.

Related conditions

These conditions work well alongside this one:

• Volatile organic compounds ratio value - Tests the volatile organic compounds ratio of one or more entities.

• Carbon dioxide value - Tests the carbon dioxide level of one or more entities.