Occupational Safety, Health and Workplace Practices
What the exam tests
This domain tests electrical, mechanical and chemical safety, personal protective equipment, isolation procedures and safe field practice.
Core rules and concepts
- Electrical work requires isolation, lockout/tagout, testing for dead and earthing checks. Never bypass an RCCB or work with wet hands.
- Before opening a pressurised line, stop the pump, close the isolation valve, drain the line and confirm the gauge reads zero.
- Chemical safety requires goggles, gloves, apron and suitable respiratory protection when handling fertilizers, acids or chlorine. Never mix chlorine and acid.
- Fertigation areas need backflow prevention and clear labelling of tanks and lines.
- Field hazards include heat stress, slips, sharp tools, trench collapse and moving machinery. Use safe trenching and keep guards in place.
- First aid and emergency contacts should be available; workers should not work alone on hazardous electrical or chemical tasks.
Worked example
A pressure gauge on a live submain must be replaced. Correct sequence: stop the pump, close the isolation valve, lock out and tag the control, open the drain valve, wait until the gauge reads zero, wear gloves and goggles, remove and replace the gauge, then close the drain, remove the lockout and restart slowly. The reasoning is that a gauge may read zero while trapped pressure remains elsewhere; draining and isolating the correct section is essential.
Traps that cost marks
- Opening a line because the pump is off but the valve is still open.
- Bypassing an RCCB to “test” a pump.
- Mixing acid and chlorine in the same tank.
- Storing fertilizer and chlorine in unlabelled containers.
- Working in a deep trench without shoring or safe access.