At year end a safety manager totals the OSHA 300 injury log onto the Form 300A summary, and payroll supplies the hours worked. Those pages hold the inputs for the two standard injury rates. The total recordable incident rate (TRIR) counts every recordable injury and illness, and the DART rate counts the subset that cost days away from work, restricted duty or a job transfer.
Both are incidence rates, meaning cases per 100 full-time workers per year. The Bureau of Labor Statistics (BLS) publishes the same two rates for every construction trade, so a contractor can set its own figures next to the national ones for its NAICS code.
The formula
BLS gives one formula for both rates: multiply the number of cases by 200,000 and divide by the hours all employees worked in the year. The 200,000 stands for 100 employees working 40 hours a week for 50 weeks, which puts every firm on the same base.
The case counts come straight off the 300A, according to the BLS instructions:
- TRIR uses column H (cases with days away from work), plus column I (job transfer or restriction), plus column J (other recordable cases).
- DART uses columns H and I only.
BLS works an example in its instructions. A fictional company with 7 recordable cases and 400,000 hours worked has an incidence rate of 3.5. Three of those cases involved time off, restricted duty or a transfer, for a DART rate of 1.5.
What makes a case recordable
OSHA’s rule at 29 CFR 1904.7 sets the criteria. A work-related injury or illness is recordable if it results in death, days away from work, restricted work or transfer to another job, medical treatment beyond first aid, or loss of consciousness. A fractured or cracked bone, a punctured eardrum, cancer and chronic irreversible disease are recordable at diagnosis, even without treatment.
The first aid list is closed, and OSHA says nothing outside it counts as first aid. Steri-Strips and butterfly bandages are first aid. Sutures and staples are medical treatment. A splint used only to transport an injured worker is first aid, while a device with rigid stays is medical treatment.
A few counting rules decide whether a case lands in H, I or J:
- Days away are counted in calendar days, starting the day after the injury, and the count can stop at 180.
- A restriction that applies only to the day of the injury does not make the case recordable as restricted work.
- If a physician recommends a restriction, the case is recorded as restricted work even when the employee keeps doing every routine function of the job.
- BLS counts a case with both days away and restricted duty as a days-away case.
Rule 3 matters most for DART. A superintendent who keeps an injured carpenter on full duty against a doctor’s note has still produced a DART case.
The hours side
BLS says hours worked should leave out paid time that is not work, such as vacation, sick leave and holidays. For salaried staff without time records, BLS allows an estimate from scheduled hours or 8 hours a workday.
If the number comes from a payroll report of paid hours, the clerk pulling it has to subtract paid time off first. The timecards that feed labor productivity by cost code are a cleaner source, since they record hours on the job.
A worked example
The figures below are an example with round numbers. A drywall and insulation contractor logged 600,000 hours worked in a year, about 300 full-time workers. Its 300A shows 2 cases in column H, 1 in column I and 6 in column J.
- TRIR: 9 cases × 200,000 ÷ 600,000 = 3.0
- DART: 3 cases × 200,000 ÷ 600,000 = 1.0
| Measure | OSHA 300A columns | Example cases | Example rate | BLS 2024 drywall and insulation (NAICS 23831) | BLS 2024 construction (NAICS 23) |
|---|---|---|---|---|---|
| Total recordable cases (TRIR) | H + I + J | 9 | 3.0 | 2.9 | 2.2 |
| Days away, restricted or transferred (DART) | H + I | 3 | 1.0 | 2.0 | 1.3 |
| Days away from work | H | 2 | 0.7 | 1.2 | 0.9 |
| Job transfer or restriction | I | 1 | 0.3 | 0.8 | 0.4 |
| Other recordable cases | J | 6 | 2.0 | 0.9 | 0.9 |
The example firm’s TRIR sits just above the 2.9 BLS reports for drywall and insulation contractors in 2024. Its DART rate is half the trade’s 2.0. Most of the firm’s cases sit in column J, where its rate of 2.0 for other recordable cases is more than twice the trade’s 0.9.
That pattern has two readings. The firm’s injuries may have been less severe than the trade’s, or some column J cases carried a physician’s restriction that was never recorded as one. Pull the medical paperwork for each J case and check it against rule 3 before reporting the DART rate to anyone.
The hours definition moves the result too. If payroll had reported 640,000 paid hours, including 40,000 hours of paid time off, the same 9 cases would give a TRIR of 2.8 and a DART rate of 0.9.
Small firms and single cases
Each case adds 200,000 divided by hours worked to the rate. A small contractor can move half a point or more on a single injury.
| Hours worked in the year | Full-time equivalent workers | Rate added by one recordable case |
|---|---|---|
| 100,000 | 50 | 2.00 |
| 250,000 | 125 | 0.80 |
| 600,000 | 300 | 0.33 |
| 1,000,000 | 500 | 0.20 |
| 2,000,000 | 1,000 | 0.10 |
At 100,000 hours, one more case adds 2.0 to TRIR. At 2 million hours it adds 0.1. A smaller contractor can also divide three years of cases by three years of hours, using the same formula, for a rate that moves less from one injury.
BLS says rates mean more when a firm is compared with employers doing similar work with workforces of similar size. It publishes rates by establishment size, along with quartile distributions by detailed industry, and its instructions walk through placing a firm against the first quartile, median and third quartile.
National rates by trade
BLS released its 2024 rates on January 22, 2026. The construction sector’s TRIR was 2.2 and its DART rate was 1.3, close to private industry’s 2.3 and 1.4. The trade rows below range from a TRIR of 1.5 to 4.6.
| Industry | NAICS | Total recordable cases | DART cases | Other recordable cases |
|---|---|---|---|---|
| Private industry | 2.3 | 1.4 | 1.0 | |
| Construction | 23 | 2.2 | 1.3 | 0.9 |
| Residential building construction | 2361 | 2.5 | 1.4 | 1.1 |
| Nonresidential building construction | 2362 | 1.9 | 1.2 | 0.7 |
| Highway, street, and bridge construction | 2373 | 2.5 | 1.5 | 1.0 |
| Framing contractors | 23813 | 4.6 | 3.4 | 1.3 |
| Plumbing, heating, and air-conditioning contractors | 23822 | 3.0 | 1.7 | 1.4 |
| Drywall and insulation contractors | 23831 | 2.9 | 2.0 | 0.9 |
| Poured concrete foundation and structure contractors | 23811 | 2.8 | 2.0 | 0.8 |
| Structural steel and precast concrete contractors | 23812 | 2.8 | 1.3 | 1.5 |
| Roofing contractors | 23816 | 2.4 | 1.7 | 0.6 |
| Electrical contractors and other wiring installation contractors | 23821 | 1.8 | 1.1 | 0.8 |
| Site preparation contractors | 23891 | 1.5 | 1.0 | 0.5 |
Framing contractors had the highest rates in the construction rows shown, with a TRIR of 4.6 and a DART rate of 3.4. Site preparation contractors were at 1.5 and 1.0. Structural steel and precast contractors had a TRIR of 2.8 but a DART rate of 1.3, because more of their cases fell in the other recordable column.
Compare your rate to the row for your own NAICS code. General contractors fall under construction of buildings (236) or heavy and civil engineering (237), and trade contractors under 238. The 2024 tables use NAICS 2017 codes. BLS has scheduled its 2025 data for November 18, 2026.
How to start on your jobs
Take last year’s 300A and compute TRIR and DART with the hours from timecards, excluding paid time off. Then compute the same two rates for each of the last three years, and look up your trade’s row in the BLS table. If column J holds most of your cases, review each one against OSHA’s restricted-work rule before the next 300A goes out.