Preexisting Conditions and OSHA Recordability: When Work Significantly Aggravates an Injury

Work significantly aggravates a pre-existing condition when it causes days away, restriction, new treatment, or other outcomes that would not have happened otherwise. A pre-existing condition is one that came solely from a non-work event or exposure.

Preexisting conditions do not automatically remove a case from OSHA recordkeeping.

An injury or illness is work-related if an event or exposure in the work environment caused or contributed to it, or significantly aggravated a pre-existing condition (29 CFR 1904.5). It is presumed for anything that happens in the work environment unless one of nine exceptions applies: the person was there as a member of the public; symptoms surfaced at work but came solely from a non-work event; voluntary wellness, fitness, or recreation; eating or drinking for personal consumption; personal tasks outside assigned working hours; personal grooming, self-medication for a non-work condition, or a self-inflicted injury; a motor vehicle accident in a company parking lot or access road while commuting; the common cold or flu; and mental illness, unless the employee voluntarily provides a qualified professional's opinion that it is work-related.

Record when a work event significantly aggravates the condition and produces an OSHA recording outcome. Deciding work-relatedness after severity is the most common ordering mistake, and it pushes borderline cases onto the log, or off it, for the wrong reason. The fix is to settle where the employee was, what they were doing, and at whose direction before anyone discusses treatment or severity.

HR safety partners often hear the sensitive details first, so privacy handling and a clear line between HR files and the OSHA log matter most.

Teams often treat any prior pain as a reason to exclude the case.

Work-relatedness is the first gate: a case that fails it never reaches the recording criteria, the 300A totals, or the rates. A case that passes still needs a recording criterion before it goes on the log.

• Medical treatment changes or new restrictions can indicate significant aggravation.
• The work environment is more than the building: it includes any location where employees work or are present as a condition of employment, and the equipment and materials they use.

An employee with an old knee injury from soccer, managed with over-the-counter pain relief, twists the knee stepping off a loading dock. The doctor now prescribes physical therapy and a week without ladder work. Work significantly aggravated the condition (new medical treatment and a restriction), so the case is recordable.

1. Document the condition before the event.
2. Document the outcome after the event.
3. Apply the four significant aggravation tests.
4. Record if an outcome would not have occurred without work.

What to keep in the case file:

• What the employee was doing, where, and at whose direction
• Whether the location is part of the work environment
• Which exception you considered and the facts that support or rule it out
• For aggravation cases, the condition before the event and what changed after it

300log keeps the facts that decide work-relatedness (where the event happened, what the employee was doing just before, and what happened) in each case's 301 fields, right next to the log entry they support.

For a quick answer without an account, use the free recordability checker.

• Travel Status Injuries and OSHA Recordkeeping: Hotels, Commutes, and Work Tasks
• Common Cold and Flu Exceptions in OSHA Work-Relatedness
• Commuting Injuries and OSHA Recordkeeping: What Usually Stays Off the Log
• Counting Days Away From Work on the OSHA 300 Log