Will a haze machine set off a fire alarm?

Do not treat a small amount as automatic permission

A light haze may be less visually obvious than a dense cloud, but that does not establish how a detector will respond. A previous event using an effect without an alarm is not proof that another room, machine or set of conditions will behave the same way.

Do not disable, cover or otherwise interfere with detectors. Decisions involving the building’s fire system belong with the authorised venue team and its procedures. If approval cannot be obtained, use a lighting approach that does not depend on the effect.

Give the venue enough information to decide

Ask who approves atmospheric effects and what documentation they require. Provide the proposed equipment, fluid information, intended position and timing. Explain whether the effect is continuous, a short cue or a low-lying look; the event team needs to understand the actual use.

• Machine and specified fluid or consumable.
• Effect location and intended duration.
• Room ventilation and nearby audience or performer activity.
• A proposed supervised test, if the venue permits one.
• The alternative look if the effect cannot be used.

Check more than the alarm response

Approval is not only about avoiding an unwanted alarm. Visibility, escape routes, performer movement and sensitivity to the effect also need consideration in the event assessment. Follow the equipment instructions and the agreed operating plan.

Reconfirm arrangements if the location, product or use changes. Keep the approval contact and operating instructions available to the person running the effect. A successful equipment test does not authorise a different quantity or location during the show.