How to do a Job Hazard Analysis (JHA/JSA): a practical guide

A Job Hazard Analysis — JHA, also called a Job Safety Analysis (JSA) or, on federal work, an Activity Hazard Analysis (AHA) — is one of the most useful tools in safety, and one of the simplest. You take a job, break it into steps, work out what can go wrong at each step, and decide how to control it. Done well, a JHA is how experienced knowledge gets written down so the whole crew works the same safe way. Done badly, it is a form nobody reads. This guide follows OSHA's method, set out in its booklet Job Hazard Analysis (OSHA 3071), and focuses on making JHAs that actually get used.

Which jobs to analyze first

You cannot analyze everything at once, so prioritize. OSHA suggests starting with jobs that have the highest injury or illness rates, jobs where a mistake could cause severe harm even if incidents are rare, jobs where a small change in routine could cause an incident, new jobs, jobs that have changed, and complex jobs that are hard to do from memory. Your OSHA 300 log and your near-miss reports are the best guide to where to start — they tell you where people actually get hurt.

Breaking the job into steps

The skill in a JHA is choosing the right level of detail. Break the job into a logical sequence of basic steps — enough that no significant hazard hides between steps, but not so granular that the analysis becomes an unusable list of tiny motions. A useful test: each step should describe what is done, not how, and a person who knows the trade should be able to follow it. Watch the job being done, ideally by an experienced worker, and involve that worker in listing the steps. People do the job; they know where the risk really is.

Finding the hazard in each step

For each step, ask what can go wrong and identify the hazard honestly. It helps to run through the common hazard categories: struck-by and struck-against, caught-in or between, falls to a lower level and slips/trips on the same level, electrical, chemical exposure and inhalation, thermal (heat and cold), noise, ergonomic and manual handling, and hazards from the surrounding environment such as traffic or the public. Ask not just "what usually happens" but "what could happen" — the point of a JHA is to catch the low-frequency, high-severity events before they occur.

Choosing controls: the hierarchy

For each hazard, choose the control using the hierarchy of controls, in order of effectiveness. First, can you eliminate the hazard entirely — change the design or sequence so it is not there? If not, can you substitute something less hazardous? Failing that, use engineering controls — guards, ventilation, barriers — that reduce exposure without relying on behavior. Next come administrative controls and safe work practices — procedures, training, rotation, permits. Personal protective equipment comes last, because it protects only the person wearing it and only when worn correctly. A JHA whose every control is "wear PPE and be careful" has skipped the most effective options.

Making it a document people use

A JHA earns its keep at the point of work, not in a filing cabinet. Review it with the crew before the task — that is what a pre-task or "tailgate" briefing is for — and get the people doing the job to sign that they have read and understood it. Keep the language plain and specific to the site. And treat the JHA as a living record: if the job changes, if an incident or near miss happens, or if the crew finds a better way, update it. On federal and many commercial projects an AHA must be reviewed and accepted before that activity starts, and updated when conditions change — a good discipline everywhere.

How JHAs connect to the rest of your program

JHAs are not an island. They should flow from your hazard assessment, feed your training (a good JHA is a ready-made toolbox talk), and connect to your incident investigations — when something goes wrong, the JHA for that task is the first thing to revisit. Kept together and current, your JHAs are also some of the strongest evidence you can show a GC or an OSHA officer that you plan work safely rather than react to incidents.