In the framework of Natech risk assessment, technological hazard refers to a potential for the occurrence of adverse effects due to the release of hazardous substances, from process or storage equipment, caused by natural-hazard impacts. It is important to identify the equipment that acts as a hazard source, and to rank the hazard in terms of the type and amount of hazardous substances it contains, its operating conditions, as well as its vulnerability with respect to natural hazards. This chapter examines these aspects to support the prioritization of specific measures for Natech accident prevention and mitigation, and to focus the application of detailed quantitative risk-analysis techniques to a limited set of accident scenarios or equipment items that are considered to be the most critical.
A hazard originating from technological or industrial conditions, including accidents, dangerous procedures, infrastructure failures or specific human activities, that may cause loss of life, injury, illness or other health impacts, property damage, loss of livelihoods and services, social and economic disruption, or environmental damage.
Table 6.1
List of Substance-Hazard Categories According to the CLP Regulation and Threshold Amounts for Lower- and Upper-Tier Installations as per the Seveso Directive (European Union, 2008, 2012)
Hazard Categories | Lower-Tier | Upper-Tier |
Amount (t) | ||
Section “H”—HEALTH HAZARDS |
||
H1 ACUTE TOXIC Category 1, all exposure routes | 5 | 20 |
H2 ACUTE TOXIC, Category 2, all exposure routes; Category 3, inhalation exposure route | 50 | 200 |
H3 STOT SPECIFIC TARGET ORGAN TOXICITY—SINGLE EXPOSURE STOT SE Category 1 | 50 | 200 |
Section “P”—PHYSICAL HAZARDS |
||
P1a EXPLOSIVES, Unstable explosives or Explosives, Division 1.1, 1.2, 1.3, 1.5, or 1.6, or substances or mixtures having explosive properties according to method A.14 of Regulation (EC) No 440/2008 and do not belong to the hazard classes organic peroxides or self-reactive substances and mixtures | 10 | 50 |
P1b EXPLOSIVES, Explosives, Division 1.4 | 50 | 200 |
P2 FLAMMABLE GASES Flammable gases, Category 1 or 2 | 10 | 50 |
P3a FLAMMABLE AEROSOLS, “Flammable” aerosols Category 1 or 2, containing flammable gases Category 1 or 2 or flammable liquids Category 1 | 150 (net) | 500 (net) |
P3b FLAMMABLE AEROSOLS, “Flammable” aerosols Category 1 or 2, not containing flammable gases, Category 1 or 2 nor flammable liquids Category 1) | 5,000 (net) | 50,000 (net) |
P4 OXIDISING GASES Oxidizing gases, Category 1 | 50 | 200 |
P5a FLAMMABLE LIQUIDS, Flammable liquids, Category 1, or Flammable liquids Category 2 or 3 maintained at a temperature above their boiling point, or other liquids with a flash point ≤60°C, maintained at a temperature above their boiling point | 10 | 50 |
P5b FLAMMABLE LIQUIDS, Flammable liquids Category 2 or 3 where particular processing conditions, such as high pressure or high temperature, may create major-accident hazards, or other liquids with a flash point ≤60°C where particular processing conditions, such as high pressure or high temperature, may create major-accident hazards | 50 | 200 |
P5c FLAMMABLE LIQUIDS, Flammable liquids, Categories 2 or 3 not covered by P5a and P5b | 5,000 | 50,000 |
P6a SELF-REACTIVE SUBSTANCES AND MIXTURES and ORGANIC PEROXIDES, self-reactive substances and mixtures, Type A or B or organic peroxides, Type A or B | 10 | 50 |
P6b SELF-REACTIVE SUBSTANCES AND MIXTURES and ORGANIC PEROXIDES, self-reactive substances and mixtures, Type C, D, E, or F or organic peroxides, Type C, D, E, or F | 50 | 200 |
P7 PYROPHORIC LIQUIDS AND SOLIDS Pyrophoric liquids, Category 1 Pyrophoric solids, Category 1 | 50 | 200 |
P8 OXIDISING LIQUIDS AND SOLIDS Oxidizing Liquids, Category 1, 2, or 3, or oxidizing solids, Category 1, 2, or 3 | 50 | 200 |
Section “E”—ENVIRONMENTAL HAZARDS |
||
E1 Hazardous to the Aquatic Environment in Category Acute 1 or Chronic 1 | 100 | 200 |
E2 Hazardous to the Aquatic Environment in Category Chronic 2 | 200 | 500 |
Section “O”—OTHER HAZARDS |
||
O1 Substances or mixtures with hazard statement EUH014 | 100 | 500 |
O2 Substances and mixtures which in contact with water emit flammable gases, Category 1 | 100 | 500 |
O3 Substances or mixtures with hazard statement EUH029 | 50 | 200 |
Table 6.2
Structural Features of Pipelines (Lanzano et al., 2014)
Pipelines | Materials | Joints | Damage Patterns |
Continuous (CP) | Steel; polyethylene; polyvinylchloride; glass fiber reinforced polymer | Butt welded; welded slip; chemical weld; mechanical joints; special joints | Tension cracks; local buckling; beam buckling |
Segmented (SP) | Asbestos cement; reinforced concrete; polyvinylchloride (PVC); vitrified clay; cast iron | Caulked joints; bell end spigot joints | Axial pull-out; crushing of bell end; crushing of spigot joints; circumferential failure; flexural failure |
Table 6.3
Technology Hazard Matrix With 1 = Low Hazard and 5 = High Hazard
Equipment | Liquefied Gas | Compressed Gas | Cryogenic Liquid | Liquid | Fine Dusts |
Pressurized (above-ground) | 5 | 4 | 4 | 2 | 1 |
Pressurized (underground) | 2 | 3 | 2 | 2 | 1 |
Atmospheric | — | — | 5 | 3 | 3 |
Pipeline (above-ground) | 4 | 3 | 4 | 2 | 1 |
Pipeline (underground) | 3 | 2 | 3 | 1 | — |
Underground equipment is considered buried or mounded.
Table 6.4
Expected Secondary Scenarios and Estimated Severity for Different Target Equipment and Loss Intensity Classesa
Loss Intensity | Expected Secondary Events for Different Target Equipment | |||
Atmospheric Equipment | Pressurized Equipment | Elongated Equipment | Auxiliary Equipment | |
LI1—Flammable | Minor pool fire | Minor jet fire | Minor pool fire; minor flash fire | Minor pool fire; minor flash fire |
LI1—Toxic | Minor evaporating pool | Boiling pool; jet toxic dispersion | Minor boiling pool; toxic dispersion | Minor evaporating pool |
LI2—Flammable | Pool fire; flash fire; VCE | Jet fire; flash fire; VCE | Pool fire; flash fire; VCE | Minor pool fire; minor flash fire |
LI2—Toxic | Evaporating pool; toxic dispersion | Boiling pool; jet toxic dispersion | Boiling pool; toxic dispersion | Minor evaporating pool |
LI3—Flammable | Pool fire; flash fire; VCE | BLEVE/fireball; flash fire; VCE | Pool fire; flash fire; VCE | Minor pool fire; minor flash fire |
LI3—Toxic | Evaporating pool; toxic dispersion | Boiling pool; jet toxic dispersion | Boiling pool; toxic dispersion | Evaporating pool; minor toxic dispersion |
Loss Intensity | Expected Severity | |||
Atmospheric Equipment | Pressurized Equipment | Elongated Equipment | Auxiliary Equipment | |
LI1—Flammable | Low | High | Low | Low |
LI1—Toxic | Low | High | High | Low |
LI2—Flammable | High | High | High | Low |
LI2—Toxic | High | High | High | Low |
LI3—Flammable | High | High | High | Low |
LI3—Toxic | High | High | High | High |
Adapted from Cozzani et al. (2006).
a VCE, Vapor cloud explosion; BLEVE, boiling liquid expanding vapor explosion. “Flammable” and “Toxic” refer to the substance in the secondary vessel damaged by the blast wave.