An AHA in construction stands for Activity Hazard Analysis. It’s a document that breaks a specific work task into individual steps, identifies the hazards associated with each step, and lists the controls that will keep workers safe. If you’ve also seen the terms JHA (Job Hazard Analysis) or JSA (Job Safety Analysis), they describe essentially the same process. OSHA uses “job hazard analysis” as its preferred term, while “activity hazard analysis” is the standard language on federal construction projects governed by the U.S. Army Corps of Engineers (USACE).
How an AHA Works
An AHA is built around a simple three-column structure: job steps, hazards, and controls. You take the activity you’re about to perform, such as erecting scaffolding or pouring a concrete slab, and list every step in sequence. Next to each step, you identify what could go wrong: a fall from height, exposure to silica dust, a struck-by hazard from overhead loads. The third column spells out exactly how those hazards will be controlled, whether through guardrails, respiratory protection, exclusion zones, or specific work procedures.
Beyond those three core columns, a standard AHA document also includes header information like the project location, contract number, date prepared, and who prepared and reviewed it. A second page typically covers the equipment to be used, training requirements, the names of competent or qualified personnel assigned to the task, and any inspection requirements that apply. The goal is to put everything a crew needs to know about performing that activity safely into a single, reviewable document.
The Risk Assessment Code
Most AHA formats include a Risk Assessment Code, or RAC, for each hazard. The RAC is determined by a simple matrix that weighs two factors: how likely the hazard is to cause an incident (probability) and how bad the outcome would be if it did (severity).
Probability is rated on a five-point scale from “unlikely” to “frequent.” Severity ranges from “negligible” to “catastrophic.” Where those two ratings intersect on the matrix gives you a code:
- E (Extremely High Risk): A catastrophic or critical outcome that is frequent or likely
- H (High Risk): Serious outcomes with reasonable probability, or catastrophic outcomes that are occasional
- M (Moderate Risk): Less severe outcomes or lower-probability serious ones
- L (Low Risk): Negligible severity or very unlikely occurrences
The overall RAC for the entire AHA is set by the highest-rated individual hazard on the document. This matters because staffing requirements can change based on that rating. Under the 2024 update to USACE’s safety manual (EM 385-1-1), any project with a residual RAC of “high” or “extremely high” on an AHA must have a dedicated safety professional assigned and physically present at the work site.
Who Writes and Signs an AHA
The contractor or subcontractor performing the work is responsible for preparing the AHA. Typically, a site superintendent or foreman with direct knowledge of the task drafts it, and a safety officer or project manager reviews it. Both the preparer and reviewer are identified by name and title on the document.
Under the March 2024 update to EM 385-1-1, every worker involved in the task must review the AHA before work begins and sign it (or sign a separate signature sheet) to confirm they understand the hazards and controls. This isn’t a formality. If conditions change mid-task and the AHA needs to be revised, work stops until the revision is complete, accepted, and re-reviewed by every affected employee. If work was halted because of a safety violation, the same rule applies: no one picks up a tool until the revised AHA is signed off.
Is an AHA Legally Required?
OSHA’s construction standards (29 CFR Part 1926) do not explicitly mention “Activity Hazard Analysis” by name. What OSHA does require is that employers “initiate and maintain such programs as may be necessary” to prevent accidents on the job site. An AHA is one of the most common ways contractors satisfy that obligation, especially for high-hazard tasks.
Where AHAs become a hard contractual requirement is on federal projects. USACE’s EM 385-1-1 safety manual makes AHAs mandatory, and any contractor working under a Corps of Engineers contract must submit them as part of the project’s safety and health plan. Many other federal agencies and large general contractors have adopted the same requirement. Even on private-sector projects where no regulation specifically demands an AHA, having one on file demonstrates that you identified hazards and planned controls before work started, which is exactly the kind of documentation that matters during an OSHA inspection or after an incident.
The 2024 USACE update also formally recognizes that JHAs, JSAs, and “similar risk management assessment tools” are acceptable substitutes for AHAs, as long as they collect the same information and develop adequate controls. So the format can vary, but the substance has to be there.
What a Good AHA Looks Like in Practice
A useful AHA is specific, not generic. Writing “wear PPE” as a control for every hazard defeats the purpose. A well-written AHA for, say, cutting concrete with a walk-behind saw would break the task into steps like marking the cut line, checking the blade condition, making the cut, and cleaning up. For the cutting step, the hazards column might list silica dust exposure, noise levels above 85 decibels, flying debris, and blade kickback. Each of those hazards would get its own targeted control: a water-fed saw to suppress dust, hearing protection rated for the noise level, a face shield, and a pre-cut blade inspection with a specific kickback prevention technique.
The equipment section would list the saw model, the water supply system, and the PPE. The training section would name the operator and confirm they’ve completed the required competency training. Inspection requirements might call for a blade check before each use and a daily equipment walkaround.
This level of detail is what separates an AHA that actually prevents injuries from one that just checks a compliance box. When workers review and sign an AHA that specifically describes their task, they’re far more likely to internalize the hazards than if they’re handed a boilerplate form.
Record Keeping
OSHA requires employers to retain injury and illness records for five years following the end of the calendar year they cover. AHAs themselves don’t have a separate federal retention period spelled out in regulation, but best practice on most projects is to keep them for the duration of the contract plus several years. Many contract specifications set their own retention timelines. Since AHAs serve as evidence that hazards were identified and controlled before an incident occurred, holding onto them protects you in the event of a future claim or audit.