The OSHA 300 log is the backbone of federal injury and illness recordkeeping. If your company is covered by OSHA's recordkeeping rule, you're required to track work-related injuries and illnesses on this form throughout the calendar year, summarize them each January, and keep the records on file for years afterward. Get the details wrong and you're looking at citations that stack up fast — OSHA can issue a separate penalty for each missing or inaccurate entry.

This guide covers who has to keep a 300 log, what actually counts as recordable, the deadlines you can't miss, and the mistakes that trip up safety managers most often.

What the OSHA 300 Log Actually Is

The OSHA Form 300, officially titled the "Log of Work-Related Injuries and Illnesses," is a running record employers use to document recordable incidents as they happen. It's one piece of a three-part system:

Form 300 – the log itself, updated throughout the year
Form 300A – the annual summary, posted every February
Form 301 – the incident report, filled out for each individual recordable case

Together, these three forms satisfy the recordkeeping requirements under 29 CFR 1904. Construction employers deal with this constantly because jobsite injury rates tend to run higher than in office-based industries, and OSHA uses this data to calculate your company's incident rates (TRIR, DART) — numbers that general contractors and owners increasingly ask for during prequalification.

Who Has to Keep One

Most employers with more than 10 employees at any point during the previous calendar year are required to maintain OSHA 300 logs, unless they fall into a partially exempt low-hazard industry listed in Appendix A of Part 1904. Construction is not on that exempt list — if you're in construction and you had more than 10 employees last year, you need a 300 log.

A few clarifications that matter on jobsites:

Employee count is based on the entire company, not a single site. A GC with 150 employees across multiple projects keeps one company-wide log, broken out by establishment if OSHA requires it.
Multi-employer worksites still require individual recordkeeping. Each subcontractor records its own employees' injuries. The host employer records injuries to its own employees and any supervised temporary workers.
Government contracts don't exempt you. Recordkeeping obligations apply regardless of who the client is.

What Counts as Recordable

This is where most disputes happen. An injury or illness is recordable if it's work-related and results in one or more of the following:

Death
Days away from work
Restricted work or transfer to another job
Loss of consciousness
Medical treatment beyond first aid
A significant injury or illness diagnosed by a physician or licensed health care professional, even without the above outcomes

The first-aid-versus-medical-treatment line trips up more superintendents than anything else. OSHA maintains a specific list of what qualifies as first aid — things like cleaning a wound, using non-prescription medication at nonprescription strength, applying a bandage, or using a hot/cold pack. If a worker gets stitches, sutures, prescription-strength medication, or a follow-up X-ray that shows a fracture, that's medical treatment, and it's recordable.

Quick Recordability Test

Scenario	Recordable?
Worker gets a splinter, pulls it out, applies a bandage	No – first aid
Worker sprains an ankle, sent home for the rest of the shift	Yes – days away from work
Worker gets stitches for a laceration	Yes – medical treatment beyond first aid
Worker develops hearing loss confirmed by audiogram showing a standard threshold shift	Yes – recordable hearing loss case
Worker takes an over-the-counter pain reliever at normal dosage	No – first aid
Worker is restricted to light duty for three days	Yes – restricted work case

When in doubt, document the incident and consult 1904.7, which lays out the general recording criteria in detail. Under-recording is just as risky as over-recording — OSHA treats a log that's missing cases as a falsified record, not a minor paperwork gap.

Deadlines You Can't Miss

Recordkeeping runs on a strict calendar:

Within 7 calendar days of learning about a recordable incident, you must enter it on the Form 300 log.
By February 1, you must post the Form 300A summary in a visible location at each establishment — typically wherever other employee notices go.
Through April 30, the 300A stays posted.
By March 2, establishments with 250+ employees (or 20-249 employees in designated high-hazard industries, which includes most construction NAICS codes) must electronically submit Form 300A data to OSHA through the Injury Tracking Application (ITA).
Retention is 5 years from the end of the calendar year the records cover. If you get hit with a citation or litigation, retain longer.

Miss the February 1 posting deadline and you've created an easy, visible violation for any inspector who walks the site during an unrelated visit.

Electronic Submission: Who's In

The ITA submission requirement has expanded over the past several years, and construction keeps getting pulled further in because of its high-hazard classification. If your NAICS code falls under construction (23-prefix codes) and you have 20 or more employees at any point in the year, assume you owe an electronic 300A submission even if your total headcount across the company is small. Establishments with 100+ employees in certain high-hazard sectors may also owe Form 300 and 301 data, not just the summary — check the current ITA rule text each year since thresholds have shifted.

Certifying and Posting the 300A

The annual summary has to be certified by a company executive — an owner, officer, highest-ranking on-site official, or an immediate supervisor of the highest-ranking official. That person is attesting the data is accurate, not just signing a form. Before certifying, review the full log line by line: check that case classifications match what actually happened, that days-away counts are correct, and that nothing recordable was left off.

Even if you had zero recordable incidents, you still have to post a 300A stating zero cases. Skipping posting because you had no incidents is itself a violation.

Common Mistakes on Jobsites

Classifying a case as first aid when it was actually medical treatment. This usually happens when a medic on-site provides treatment that crosses the line — prescription-strength medication, suturing, or immobilizing a joint with more than a basic wrap.

Forgetting to update day counts. If a worker is out for two weeks and you logged one day initially, you need to go back and update the entry once the actual duration is known. OSHA requires updates to the log for up to one year after the case closes.

Confusing privacy cases. Certain cases — sexual assault, mental illness, HIV infection, needlestick injuries — must be logged without the employee's name to protect privacy. Many employers either skip logging them or accidentally include identifying details.

Not reconciling 300A totals with the underlying 300 log. The summary numbers should tie directly back to the detailed entries. Auditors and insurance carriers catch discrepancies here constantly during mod-rate reviews.

Losing track of multi-employer responsibilities. On a jobsite with several subs, it's easy to assume someone else recorded an incident. Confirm in writing who owns the recordkeeping obligation for each crew.

Recordkeeping vs. Reporting: Don't Mix Them Up

The 300 log obligation is separate from OSHA's severe injury reporting requirement. A fatality must be reported to OSHA within 8 hours, and an inpatient hospitalization, amputation, or loss of an eye must be reported within 24 hours — regardless of whether the case ends up recordable on the log. Logging and reporting run on different clocks and different triggers; missing one doesn't excuse missing the other.

Penalties for Getting It Wrong

Recordkeeping violations fall under the same penalty structure as other-than-serious or serious violations, and as of recent years the maximum per violation has climbed into the tens of thousands of dollars. Because each missing entry, each unposted 300A, and each misclassified case can be cited separately, recordkeeping penalties add up faster than a single safety violation on a jobsite walk. Falsification of records carries the potential for criminal referral in extreme cases, though that's rare in practice.

Keeping the Process Manageable

Most companies that struggle with 300 logs aren't trying to hide anything — they're just inconsistent about capturing incidents as they happen, especially across multiple active sites with different foremen reporting up different chains. Building a habit of documenting every incident report, near-miss, and first-aid visit at the time it occurs, rather than reconstructing it weeks later, is what keeps the log accurate. Some safety teams use Site Safety AI to generate consistent incident documentation and toolbox talks tied to the hazards they're actually seeing on-site, which makes it easier to cross-check what belongs on the 300 log against what crews reported in the field.

The OSHA 300 log isn't complicated in concept — track it, summarize it, post it, keep it. The difficulty is consistency: catching every recordable case, classifying it correctly, and updating it when circumstances change. Build that discipline into your weekly routine, not just your January scramble, and the annual summary takes care of itself.

FAQ

Do I need to keep an OSHA 300 log if I have fewer than 10 employees?

Generally no. Employers with 10 or fewer employees at all times during the last calendar year are partially exempt from routine recordkeeping, regardless of industry. You still must report fatalities and severe injuries within OSHA's separate reporting timelines.

How long do I have to keep OSHA 300 logs?

Five years from the end of the calendar year the records cover. If the records relate to an open claim, litigation, or OSHA citation, keep them longer until that matter is fully resolved.

Does a recordable case always mean someone missed work?

No. Medical treatment beyond first aid, restricted work, job transfer, loss of consciousness, or a significant diagnosed injury can all make a case recordable even if the employee never misses a shift.

What's the difference between the 300 log and the 300A summary?

The 300 log is the detailed, ongoing record of each recordable case updated throughout the year. The 300A is a year-end summary of total cases, days away, and case types that gets posted publicly and, for many employers, submitted electronically to OSHA.

Can a jobsite incident be recordable but not reportable, or vice versa?

Yes. Recordability and the 8-hour/24-hour severe injury reporting rule are separate systems with separate criteria. A fatality or hospitalization must be reported on its own timeline even before you've finished classifying it for the 300 log.

OSHA 300 Log Requirements: What Every Employer Needs to Know