What defines a Group II flame effect?

A Group II flame effect is characterized as an individual or group effect that is designed for unattended outdoor operation. This classification indicates that the flame effects are set up in a manner that does not require continuous human oversight during their use, making them suitable for scenarios where it is impractical or unsafe for personnel to remain present. Such effects may be employed in various outdoor settings, providing a visually striking spectacle for audiences, while being designed to operate safely without direct supervision.

The rationale for this classification emphasizes safety protocols and operational guidelines, ensuring that these effects are utilized in environments where potential risks can be managed effectively even in the absence of constant human presence. It is essential that such flame effects include adequate safety measures, such as automatic shut-off mechanisms or precautions against environmental factors that might alter their behavior.

The other choices do not meet the specific criteria established for Group II classification. For instance, attended effects designed for short-term use pertain to a different group, while effects installed in a structure or used exclusively indoors would likewise fall under separate categories that encompass different operational considerations and safety requirements outlined in the NFPA 160 standard.