A 4-gas meter alarms at 10% LEL. What does this typically indicate, and what action is appropriate?

1. The atmosphere is at full lower explosive limit — flash will occur immediately
2. A defined fraction of the lower explosive limit is present; ventilate and reassess; do not perform ignition tasks
3. Oxygen is being consumed — increase oxygen with a hose stream
4. Carbon monoxide is at lethal levels — initiate cardiac monitoring