Design for Safety

Question 1

Name the hazard effect categories

Answer 1

• Pollution
• Chemical reactions and reactivity
• Toxicity
• Mechanical failure
• Corrosion
• Nuclear radiation
• Small event leading to larger event
• Fire and explosions

Question 2

What can hazards affect?

Answer 2

• Finance – company cash flow
• Environment – land, air, water
• Personnel – employees and public
• Property – storage facility, plant equipment, lab, warehouse, office etc.

Question 3

How can hazards be controlled?

Answer 3

• Containment
• Elimination
• First aid measures
• Reduced frequency and effect

Question 4

What are strategies for reducing hazards?

Answer 4

• Chemical process – stable and harmless process for product creation
• Reduce inventory – less risk of toxic, dangerous, flammable emergencies
• Reduce pressure – slower rate of fluid escaping from vessel
• Reduce temperature – less vapour => less vapour spread, less risk of fire
• Reduce process complexity – easy for operators to understand
• Increase distance between equipment – less risk of fire escalation, better ventilation
• Reduce operator exposure –control from remote position
• Analyse equipment layout – incompatible systems kept apart
• Avoid use of highly reactive chemicals
• Reduce risk of ignition source with flammable fluids

Question 5

What are the conceptual design: building blocks?

Answer 5

• Block 1 – chemical, physical and toxicological properties
• Block 2 – effluent
• Block 3 – feedstock/product handling
• Block 4 – plant layout
• Block 5 – process equipment
• Block 6 – risk assessment