Personal Safety and Process Safety

Personal safety concerns events that harm one or a few people: slips, falls, cuts, vehicle incidents. They are frequent, low consequence, and measured by injury rates. Process safety concerns loss of containment of hazardous material or energy: fires, explosions, toxic releases. They are rare, catastrophic, and injury rates say nothing about them.

The fatal confusion

Multiple major accident investigations have found organisations congratulating themselves on record-low injury rates in the months before a disaster. The metrics were genuine; they simply measured a different thing. Slip-and-trip performance does not predict whether a corroded pipe will fail.

	Personal safety	Process safety
Frequency	Frequent	Rare
Consequence	Usually limited	Potentially catastrophic
Main controls	Behaviour, PPE, supervision	Design, engineering integrity, procedures
Useful measures	Injury rates, observations	Barrier health, integrity backlog, LOPC events

A site can be excellent at personal safety and simultaneously accumulating the conditions for a disaster. Both must be managed, and they need different data.