Sheet 23Mix-up sheet · Safety programs, inspections and training
TRIR and the OSHA 300 log for the STSC
TRIR, the total recordable incident rate, is the number of OSHA-recordable cases multiplied by 200,000 and divided by the hours your employees actually worked. The 200,000 stands for 100 full-time workers at 40 hours a week for 50 weeks, so a 12-person framing crew and a 600-person contractor land on the same scale.
The OSHA 300 log under 29 CFR 1904 is a list: one line for each recordable injury or illness, entered within 7 calendar days of learning about it. TRIR turns that list into a rate, so the size of the workforce stops distorting it. Three cases mean one thing on a job that logged 40,000 hours and something else on a job that logged 900,000.
Two slips throw a rate off: dividing by headcount instead of hours, and reaching for the old 1,000,000-hour base from ANSI Z16.1. Work in hours and 200,000. The rate is only as honest as the log behind it, which is why most of this sheet is about what goes on the log. Inspections, audits and training records sit on the parent sheet, safety program, inspections and training.
Talking point 02
Working a rate by hand
Total the hours
Use hours actually worked by employees, taken from payroll or timecards. Say the contractor's crews logged 400,000 hours this year.
Count the cases
For TRIR, every recordable case on the 300 log. For the DART rate, only the cases with days away, restricted work or a job transfer. Say there were 5 recordables, 2 of them DART cases.
Multiply, then divide
5 × 200,000 ÷ 400,000 = 2.5 TRIR. The same arithmetic on the 2 DART cases gives a DART rate of 1.0.
Read the answer back
A rate is cases per 100 full-time workers over a year. A TRIR of 2.5 means two and a half recordables for every hundred people working a full year.
Talking point 03
First aid or medical treatment
Care that keeps a case off the log and care that puts it on, 29 CFR 1904.7scroll →
Care given
Counts as
Why
Tetanus shot
First aid
The only immunization on the first-aid list
Any other vaccine
Medical treatment
Not on the list
Hot or cold therapy
First aid
Listed in 1904.7(b)(5)(ii)
Elastic wrap or other non-rigid support
First aid
Non-rigid means of support are listed
Rigid splint
Medical treatment
Rigid immobilization is first aid only when used to transport the patient
Wound closed with staples or surgical glue
Medical treatment
Closing devices like these are treatment
Medicine at prescription strength
Medical treatment
Strength decides, even for a drug sold over the counter
X-ray or observation only
Neither
A diagnostic visit is not treatment; what it finds decides the case
The first-aid list in 1904.7(b)(5)(ii) is closed: care that is not on it is medical treatment. Rule text as of October 2026.
Talking point 04
The recordkeeping year
Within 7 days
Enter the case
On the 300 log and a 301 incident report or an equivalent form, counted in calendar days from when you learn of it.
After year end
Certify the summary
The Form 300A totals the log and is certified by a company executive: an owner, a corporate officer, the most senior company manager at the site, or that person's supervisor.
Feb 1 to Apr 30
Post it
Where employee notices usually go. A year with no cases still gets a posted summary showing zeros.
5 years
Keep it
Counted from the end of the year the records cover, with the 300 log updated if a case changes.
Talking point 05
Leading and lagging indicators
Lagging
Measures of harm after it happened: TRIR, the DART rate, workers' compensation costs and the experience modification rate (EMR), which looks back over three years.
Leading
Measures of activity before harm: training completed, site walkthroughs done, corrective actions closed on time, safety observations logged. OSHA's guide to leading indicators recommends tracking both kinds.
Talking point 06
On the log or off it?
Work the rate card on scratch paper before you pick. Once you answer, every option shows its note.
Card 1 of 6 · 0 right
Card 1
A contractor recorded 3 OSHA-recordable cases during a year in which its employees worked 150,000 hours. What is its total recordable incident rate (TRIR)?
Pick an answer. A short note for each option, A to D, appears here.
AThis is what a 100,000-hour base produces; OSHA incidence rates are normalized to 200,000 hours, the yearly hours of 100 full-time workers.
BThis figure comes from a misplaced decimal point; the standard calculation gives ten times this value.
CA 1,000,000-hour base, an older convention, produces this figure rather than the OSHA incidence rate.
DCorrect: the rate is cases × 200,000 ÷ hours worked, so 3 × 200,000 ÷ 150,000 = 4.0 per 100 full-time workers.
Card 2
A worker's hand laceration is closed with sutures at a clinic. The project manager asks the supervisor to log it as first aid to protect the project's incident rate. What should the supervisor do?
Pick an answer. A short note for each option, A to D, appears here.
AThe 7-day window is a deadline for entering the case, not a waiting period to see how the wound develops.
BRecordability depends on the treatment given, and the worker's opinion or signature cannot turn sutures into first aid.
CCorrect: sutures are medical treatment beyond first aid under OSHA recordkeeping, so the case is recordable no matter how it affects the rate.
DReturning the same day only means no days away are counted; the case is still recordable because of the sutures.
Card 3
What is a leading indicator of safety performance on a construction site?
Pick an answer. A short note for each option, A to D, appears here.
AWorkers' compensation claims count injuries after they happen, which makes them a lagging indicator.
BCorrect: near-miss reports surface hazards before anyone is hurt, which is what defines a leading indicator.
CLast year's recordable rate looks backward at injuries already suffered, so it is a classic lagging measure.
DCitations reflect violations found after an inspection, and mostly whether OSHA visited, so they lag rather than predict performance.
Card 4
A roofer falls through a skylight opening and is admitted to the hospital overnight as an in-patient. No one was killed. How soon must the employer report the hospitalization to OSHA?
Pick an answer. A short note for each option, A to D, appears here.
AToo short for this case. The 8-hour deadline is for a work-related fatality, not an in-patient hospitalization.
BFar too late. OSHA reporting does not wait for the investigation; severe injuries are reported within hours.
CCorrect: 29 CFR 1904.39 requires an in-patient hospitalization, amputation, or loss of an eye to be reported to OSHA within 24 hours of the employer learning of it.
DThis mixes up two rules. Seven calendar days is the deadline to record a case on the 300 log, not to report it to OSHA.
Card 5
A laborer's forearm cut is closed in the site trailer with butterfly bandages, and the worker takes a nonprescription pain reliever at the label dose. No other care is given. How should the supervisor classify the case for OSHA recordkeeping?
Pick an answer. A short note for each option, A to D, appears here.
ACorrect: Butterfly bandages and over-the-counter medicine at label strength are on OSHA's first aid list in 29 CFR 1904.7, so a case with only that care is not recordable.
BNot for butterfly bandages. Sutures or staples are medical treatment, but butterfly bandages and Steri-Strips are first aid.
COnly prescription medication, or a nonprescription drug at prescription strength, makes a case recordable. A label dose is first aid.
DWork-related is not enough. A case must also meet a recording criterion, such as medical treatment beyond first aid or days away.
Card 6
After a supervisor began writing up workers involved in near misses, the crew's near-miss reports dropped from about ten a month to none. What does this MOST likely indicate?
Pick an answer. A short note for each option, A to D, appears here.
ANothing about the form changed. The drop followed the write-ups, which points to fear of discipline.
BFewer reports is not fewer near misses. Performance cannot be judged from a count that people stopped feeding.
CHazards rarely vanish all at once, and a drop to zero right after the write-ups began points to reporting, not to the site.
DCorrect: Punishing people involved in near misses teaches the crew to stop reporting them, so the hazards go unseen.