What it means
Severity rate measures how much time was lost because of injuries and illnesses, instead of how many cases there were. Two sites can have the same case count and very different severity.
The formula: severity rate = (total days away from work x 200,000) / total hours worked by all employees in the same period.
Companies define it in different ways. Some count only days away. Some add restricted days. Say which you used. This page uses the 200,000 hour base OSHA uses for its other rates, and the days-away version.
Why it matters
A rate built on case counts treats a paper cut and a broken leg the same. Severity rate shows whether the injuries you're having are getting worse, even when the count stays flat.
What it looks like on a site
- The lead adds up days away from the 300 Log for the period.
- The same hours figure used for TRIR goes in the bottom of the formula.
- The report says whether restricted days were included.
- A rising severity rate with flat case counts sends the lead to look at the types of injury.
This is general information, not legal advice. Check the current rule and your own procedures. Back to the glossary