Glossary · Hazards and harm
Line of fire
In machine safety, the line of fire is the path in which a person may be struck, crushed, sprayed or otherwise exposed if energy is released, for example along the travel path of a load or in front of a pressurized fitting.
- Machine safety
- Human factors
- Maintenance
In one sentence
The line of fire is the path a person would be in if stored energy or motion were suddenly released, and it depends on the task at hand.
Example
Before loosening a fitting on a hydraulic press, the maintenance technician stands to the side rather than in front of it, because trapped pressure could spray oil or throw out the fitting.
How it applies
- Machine safety: The concept turns stored energy and motion into a spatial question: where would a person be hit if the energy were released now? It complements the hazardous zone, which is based on the machine's normal motion.
- Maintenance: Line-of-fire exposure is typical when releasing springs, tensioned belts, pressurized lines or suspended loads. Even after lockout/tagout, residual energy can remain.
- Technical documentation: Tell the reader where to stand, not only what to do. A figure showing the safe position is often clearer than text.
- Evidence: Job hazard analyses and procedures should record the line-of-fire positions for each task.
Line of fire vs. hazardous zone
The hazardous zone is defined by the machine. The line of fire depends on the task and the energy being released, and it can extend beyond the zone.