When does OSHA call for an incident investigation?
| Situation | What the paragraph asks | 29 CFR |
|---|---|---|
| Process safety management | Investigate each incident that resulted in, or could reasonably have resulted in, a catastrophic release; start no later than 48 hours after (1910.119(m)(1), (m)(2)) | 1910.119(m) |
| Construction under a fall protection plan | After a fall or a related serious incident, investigate whether the plan needs to change and implement the changes (1926.502(k)(10)) | 1926.502(k)(10) |
| Any other incident | No general investigation rule; OSHA's 2015 guide is advisory | None |
What goes in an incident investigation report
OSHA's guide, Incident [Accident] Investigations: A Guide for Employers (December 2015), ends with a model form in five sections, and this form follows them:
- Information: the company, the date, the investigators and their titles.
- Incident description and injury information: the employee, the job, the date, time and place, and what happened before, during and after, with witness accounts.
- Root causes: what caused or allowed the incident to happen.
- Recommended corrective actions to prevent future incidents.
- Corrective actions taken, and the root causes they address.
Under process safety management, the report holds at a minimum the date of the incident, the date the investigation began, a description, the factors that contributed and any recommendations (29 CFR 1910.119(m)(4)), and it is reviewed with all affected personnel whose job tasks are relevant to the findings (1910.119(m)(6)). The article what goes in an incident investigation report goes section by section.
Finding the root cause
The guide puts it plainly: “Determining the root cause is the result of persistently asking ‘why’.” It names the areas where contributing factors are usually found: equipment and machinery, tools, procedures, training, and the work environment. The filled example on this page shows the method on a cut hand at a packing station, five whys down to a missing safety review, with an owner and a date for each fix. The guide names no method; the article on 5 Whys and fishbone on a jobsite compares the common ones, and how long an investigation should take sets a timetable you can defend.
The investigation and the OSHA 301
They are two documents. A recordable injury or illness goes on the OSHA 300 Log and on a 301 within seven calendar days of receiving information that it occurred (29 CFR 1904.29(b)(3)), and the free OSHA 301 form fills it. The investigation covers every incident, near misses included; the article is a near miss OSHA recordable explains where a near miss stands, and the free near miss report captures one. The OSHA recordkeeping guide covers the rest of part 1904.
What OSHA cited most on severe injury reporting in FY2025
| Paragraph | What it covers | FY2025 citations |
|---|---|---|
| 1904.39(a)(2) | In-patient hospitalization, amputation or loss of an eye reported within 24 hours | 682 |
| 1904.39(a)(1) | Fatality reported within 8 hours | 117 |
| 1904.39(a)(3) | How to report: phone, in person or online | 1 |
| 1904.39(b)(7) | Reporting after learning of a case later | 1 |
1904.39: 801 citations in FY2025 at 786 inspections, 241 of them at construction sites (NAICS 23). Citation items issued Oct 1, 2024 to Sep 30, 2025, counted by HazComFast on U.S. Department of Labor enforcement data (extracted Oct 13, 2026). Inspected establishments, not the whole industry.
Questions about incident investigations
Does OSHA require an incident investigation?
Only in specific standards. Under process safety management, each incident that resulted in, or could reasonably have resulted in, a catastrophic release of a highly hazardous chemical is investigated (29 CFR 1910.119(m)(1)). Under a 1926.502(k) fall protection plan, a fall or a related serious incident such as a near miss is investigated to decide whether the plan needs to change (1926.502(k)(10)). Outside such rules, OSHA's 2015 guide recommends investigating every incident, including close calls, and is advisory.
How long do you have to complete an incident investigation?
OSHA sets no deadline to complete one. Process safety management sets a start: as promptly as possible, no later than 48 hours after the incident (29 CFR 1910.119(m)(2)). The clocks people confuse with it are recordkeeping ones: a recordable case goes on the 300 Log and a 301 within seven calendar days (1904.29(b)(3)), and a fatality is reported within eight hours, a hospitalization, amputation or loss of an eye within twenty-four (1904.39(a)).
Is the investigation report the same as the OSHA 301?
No. The OSHA 301 records a recordable injury or illness, with its own items, within seven calendar days of learning of it (29 CFR 1904.29(b)(3)). The investigation report looks for why it happened and what will prevent it, for any incident, recordable or not. Keep both.
Who should investigate?
OSHA's guide says investigations are most effective when managers and employees conduct them together as a team, and that when a temporary worker is involved, both the staffing agency and the host employer investigate. Under process safety management, the team includes at least one person knowledgeable in the process, and a contract employee if the incident involved a contractor's work (29 CFR 1910.119(m)(3)).
Who signs an incident investigation report?
OSHA does not say. The model form in its guide has no signature line, and the process safety management paragraph asks for the report to be reviewed with all affected personnel whose job tasks are relevant to the findings (29 CFR 1910.119(m)(6)), not signed. Most companies have the investigator sign and a manager approve, and record who reviewed it.
How long should investigation reports be kept?
Process safety management reports are retained for five years (29 CFR 1910.119(m)(7)). Outside that standard OSHA sets no period for investigation reports. The OSHA 301 for a recordable case is kept five years after the end of its calendar year (1904.33(a)).
Sources and verification
- OSHA, Incident Investigation, and its guide Incident [Accident] Investigations: A Guide for Employers (December 2015)
- 29 CFR 1910.119, Process safety management
- 29 CFR 1904.39, Reporting fatalities, hospitalizations, amputations and losses of an eye
- 29 CFR 1926.502, Fall protection systems criteria and practices
Verified against the eCFR on Oct 20, 2026 (title 29 current to Oct 16, 2026) and against OSHA's guide read the same day. State Plan states enforce their own standards, which may go further than the federal ones. Not legal advice.
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