Dear Mr. Ashok,
First of all, let me welcome you to the forum. This is a great platform where people share their knowledge and experiences with an open mind. I hope you will benefit from this forum.
Now, let me address your queries.
Hazard - Anything that has the potential to cause harm.
Risk: The likelihood (probability) that someone will be harmed.
Risk = Exposure × Severity × Probability
Risk Assessment - A systematic and structured process where hazards in a workplace, or arising from workplace activities, are identified, risks assessed/evaluated, and decisions prioritized to reduce risks to acceptable levels. Please refer to the attached file for a more in-depth understanding of the topic.
When defining control measures, the prevention hierarchy needs to be considered. The highest priority should be given to elimination:
1. Elimination: Eliminating the hazard
2. Substitution: Reducing risk at the source or removing the source
3. Engineering Control: Implementing engineering solutions
4. Administrative Control: As defined in JSA/SWP, work instructions, and training
5. PPE: Ensuring people wear proper PPE
I hope this information helps you in some way.