SIF and FPI: measuring what actually kills people

Two acronyms come up constantly in HSE conversations right now — SIF and FPI — and they’re often used as if they’re the same thing. They’re not: they come from different organisations and measure slightly different things. But both exist because of the same uncomfortable finding: your Total Recordable Injury Rate tells you almost nothing about your risk of a fatality.

The problem both were built to solve

Safety research — most visibly the Campbell Institute’s work at the US National Safety Council, and IOGP’s own decades of member safety data — keeps finding the same pattern: workplaces with a low TRIR or LTIFR can still have a fatality, and workplaces with a high recordable rate often go years without one. Minor injuries (sprains, cuts, first-aid cases) and fatal or life-altering injuries tend to come from different activities and different failure modes. A falling TRIR is not evidence that your fatality risk is falling — it mostly tells you about low-energy, low-consequence events, which dominate the count.

Both SIF and FPI respond to this by measuring severity potential directly, instead of assuming the frequency of minor injuries predicts the frequency of fatalities.

SIF — Serious Injury and Fatality

SIF methodology was developed by safety researchers (notably Thomas Krause at BST) and popularised by the Campbell Institute at the National Safety Council. It’s now standard practice across US onshore oil and gas through the Onshore Safety Alliance (OSA), and widely used in construction and mining as well.

• Definition. A SIF is an incident, or a near miss, that results in — or had the realistic potential to result in — a fatal or life-altering injury.
• Two categories. An actual SIF is one that happened. A potential SIF (pSIF) is a near miss or lower-severity incident that could have become a SIF if one or two factors had been different — also called a SIF precursor, or a high-potential event.
• The precursor idea is the useful part. A SIF precursor is a high-energy source (a fall from height, vehicle traffic, mobile equipment, electrical or mechanical energy) combined with a direct exposure to that energy with no adequate control in place — regardless of whether anyone was actually hurt. That reframes a near miss from “nothing happened, move on” into “the only thing between this and a fatality was luck.”

Worth noting: OSA’s own SIF categories — Bypassing Safety Controls, Confined Space, Driving, Energy Isolation, Hot Work, Line of Fire, Safe Mechanical Lifting, Work Authorization, Working at Height — are essentially the same nine areas as the IOGP Life-Saving Rules. Different organisations, same short list of activities that kill people.

FPI — Fatality and Permanent Impairment

FPI is IOGP’s own standardised metric, first published in 2022 and reported by IOGP member companies into IOGP’s central safety database — the largest safety performance dataset in the exploration and production industry.

• Definition. FPI = fatalities plus permanent impairment injuries. Permanent impairment is precisely defined: the outcome of a work-related injury from a single acute incident, from which the worker isn’t expected to return to their pre-incident level of function — physical, psychological, or social — assessed within 180 days, against criteria aligned to the AMA Guides (Sixth Edition) and the WHO’s International Classification of Functioning. That’s a materially tighter bar than “lost time”: someone can lose no work time at all and still meet the FPI criteria if the loss of function is permanent.
• Its own rate metrics. IOGP calculates FPIR (Fatality and Permanent Impairment Rate) and PIR (Permanent Impairment Rate) the same way it calculates its long-standing Fatal Accident Rate — per 100 million work hours, not the 1-million-hour denominator TRIR and LTIFR use. That’s deliberate: at 1 million hours, fatality and permanent-impairment counts are usually zero for a single operation, which makes the rate statistically meaningless. A 100-million-hour denominator produces a number that actually moves.
• High-potential events. IOGP tracks these alongside FPI — an event that could, under slightly different circumstances, have realistically resulted in a fatality. It’s the same idea as SIF’s “potential” category under a different name.

Using them alongside TRIR, not instead of it

Neither SIF nor FPI replaces TRIR or LTIFR — they sit alongside it as a severity lens the frequency metric can’t provide on its own. In practice, that means:

• Classify by potential severity at the point of capture, not just actual outcome — a “no injury” near miss involving unguarded energy at height gets flagged with the same weight as if someone had actually been hurt.
• Route anything SIF-potential or high-potential straight into investigation — the same way a failed critical control should. The near miss is the free lesson; treat it like one.
• Track SIF/FPI counts and rates as their own leading indicator, separate from overall TRIR — a rising SIF-potential trend against a flat TRIR is the signal that actually matters.

Contego classifies every observation and incident against both severity potential and the Life-Saving Rule or critical control it touches, so a SIF precursor doesn’t get buried in the same bucket as a paper cut. See it running.