Fog machine

Fog machines are devices which create an artificial fog effect by vaporizing water solvent into the air. Typically used in industry, they can be purchased for consumer use in Halloween stores.

The fog is more dense than air, so it tends to drift downward. 

Uses

Typically, a fog machine is placed on the ground, or on a table, hidden from sight. This allows for a more emersive decor. The fog gives an unsettling feeling to the area; it disperses light and limits visibility. Moreover, it can smooth over unwanted details in the decor.

The fog will take the color of whatever lights are surrounding it.

When used outside, it gives the impression of the witching hours: the small hours in the morning when the air is most cool and allows the moisture in the air to condense.

Often used with:

• Graveyard decor
• Haunted houses
• Bubbling cauldrons

Health concerns

It is best to use a fog machine in a well-ventilated space. While the fog is harmless in small quantities, it can push air from the room and cause oxygen deprivation. This is uncommon in consumer devices.