How to compute workplace accident statistics?
Strategic Accident Management: Beyond the numbers.
Why measure accident rates?
We can't manage what we don't measure. Statistical analysis of workplace accidents is not just an administrative requirement; it is the historical memory of our prevention efforts. When we rigorously analyze past experience, we don't just see failures — we obtain the roadmap to design prevention plans that actually work, and we validate whether the policies we have implemented in the field are producing tangible results.
What are these statistics really for?
In practice, the methodical organization of this data lets us:
- X-ray the causes: Identify, evaluate and ultimately neutralize the factors that cause incidents.
- Evidence-based policies: Build safe-work procedures based on facts, not assumptions.
- Economic impact: Quantify both direct and indirect costs (lost profits, equipment damage, etc.).
- Benchmarking and evolution: Compare performance across periods to verify whether the Safety Service guidelines align with the indicators required by law.
Key indicators per the COVENIN 474 standard
For the information to be comparable and valid, we follow the COVENIN 474 standard — "Recording, classification and statistics of work-related injuries". It is the responsibility of the Occupational Safety and Health Committee to oversee these three metric pillars:
1. Gross Frequency Index (IFB)
This indicator gives us the overall picture of the volume of injuries at the company, regardless of whether they caused lost time. It relates total incidents to the actual exposure of personnel.
- NLT
- Total recorded injuries.
- HHE
- Man-hours of exposure (real time exposed to the risk).
- K
- Standardization factor (1,000,000 hours).
2. Net Frequency Index (IFN)
Here we measure operational severity. This index focuses exclusively on injuries that forced the worker to stay off the job (lost time).
- NLPT
- Lost-time injuries.
- HHE
- Man-hours of exposure.
3. Severity Index (IS)
Perhaps the most critical figure for understanding the real impact of accidents. It does not just count how often we get injured but how hard each event hits us, summing rest days and days charged for permanent disabilities.
- TDC
- Charged days (per the standard's severity table).
- TDP
- Days lost to actual medical leave.