Strong acids or bases can be corrosive BC ripping away or shoving on electrons can cause metal dissolution.
You add the strong acid or base to the diluent (usually water) because the resulting splash will never be that concentrated. And it generates less heat per unit mixed.
HAZOP
Fully qualitative risk assessment
LOPA
Semi quantitative risk assessment for individual failure modes in a system
How to
Identify Hazardous Scenario:
Example → Overpressure of a reactor leading to rupture.
Determine Initiating Event Frequency (IEF):
How often could the initiating event (e.g., valve failure) happen? → e.g., once every 1,000 years (1×10⁻³ per year)
Identify Independent Protection Layers (IPLs): IPLs are safeguards that work independently to prevent or mitigate the consequence. Examples:
Pressure relief valve (PRV)
High-pressure alarm with operator action
Emergency shutdown system (ESD)
Assign Probability of Failure on Demand (PFD) to each IPL:
→ How likely is that safeguard to fail when needed? Example: 1×10⁻²
Calculate Residual Risk:
→ Multiply initiating event frequency by the PFDs of the IPLs
→ Compare residual risk to company or industry tolerable risk criteria.