In this module
Objectives covered: LO 2.4.1. By the end you will be able to:
- Break a job into basic steps.
- Identify the hazards in each step and the controls for each hazard.
- Complete a simple JHA form and keep it up to date.
4.1 What is a JHA?
A Job Hazard Analysis (JHA), also called a Job Safety Analysis (JSA), looks at one job at a time. It breaks the job into steps, finds the hazards in each step, and writes down how each hazard will be controlled. OSHA publication 3071 describes the method.
4.2 Which jobs first?
- Jobs with the most injuries or near misses.
- Jobs where one mistake can cause a fatality or serious injury.
- New jobs, or jobs that have changed.
- Jobs that are complex enough to need written instructions.
4.3 The four steps of a JHA
- Pick the job and involve the people who do it.
- Break it into steps, usually 5 to 10. Each step starts with an action word: "Lift", "Open", "Connect". Too many steps makes the JHA hard to use; too few hides hazards.
- Identify the hazards in each step. Ask: what can go wrong? What energy is present? Can someone be struck, caught, fall, be burned, be shocked, or breathe something harmful?
- Decide the controls for each hazard, starting from the top of the hierarchy of controls.
4.4 Example: changing a cartridge filter on a dye-house water pump
| Step | Hazard | Control |
|---|---|---|
| 1. Isolate pump | Pump starts during work | Switch off, lock and tag the breaker; try to start to verify |
| 2. Release pressure | Hot water spray under pressure | Close suction and discharge valves; open drain slowly; face shield and gloves |
| 3. Open housing | Pinched fingers, heavy lid | Use correct tool; two people for lid over 23 kg |
| 4. Remove old cartridge | Chemical residue on skin and eyes | Nitrile gloves, goggles; place cartridge in labelled bag |
| 5. Fit new cartridge and close | Leak from wrong seating | Check O-ring; tighten in cross pattern |
| 6. Restore and test | Leak, unexpected start of others | Remove own lock only; open valves slowly; check for leaks |
- Watch the job being done; do not write it from the office.
- Write controls that are specific: "nitrile gloves" not "use PPE".
- Review the JHA after an incident, a change, or at least once a year.
- Use the JHA to train new workers.
- OSHA 3071, Job Hazard Analysis.
- ISO 45001 clause 8.1: operational planning and control.
- Oil and gas companies often call a short field version a Toolbox Talk or Take 5, done just before the job starts.
At a gas field operated in Sylhet, every non-routine maintenance task needs a JSA signed by the performing crew and the area authority. When a crew prepared to replace a flange gasket, the JSA discussion revealed that the line had not been purged of condensate. Adding a purge and gas test step before breaking the flange prevented a possible hydrocarbon release.
Learning Check
Answer these two questions to check your understanding. You can try again as many times as you like.