A hazardous material is a substance or combination of substances which, because of quantity, concentration, physical, chemical or infectious characteristics may either:

1. cause, or significantly contribute to an increase in deaths or serious illness; or
   
2. pose a substantial present or potential hazard to humans or the environment.

More specifically, hazardous materials have one or more of the following properties:

	flammable;
	corrosive or irritant;
	oxidizing;
	explosive;
	radioactive;
	infectious;
	thermally unstable or reactive; or
	poisonous (including carcinogens, mutagens, and teratogens).

While hazardous materials are commonly associated with manufacturing and industrial areas, they are also associated with retail and commercial businesses.

	Gas stations have gasoline, oils, and cleaning solvents.
	Retail stores sell automotive products, pesticides, cleaning supplies, paints, and swimming pool chemicals.
	Warehouses and transfer facilities may temporarily or commonly handle hazardous materials.
	Plating, printing shops, dry cleaners all have specialty chemicals necessary for their operations.
	Grocery stores have refrigeration facilities that may contain hazardous materials.
	Even something as innocuous as a florist has helium to fill balloons.

• Almost all hazardous materials incidents result from ground shaking. One depiction of the ground shaking hazard are ABAG's ground shaking hazard maps. However, the number and severity of hazardous materials incidents depends not only on the severity of shaking, but also on the design of facilities. For example, unreinforced masonry and poorly engineered tilt-up concrete and concrete frame buildings can be quite susceptible to catastrophic structural damage. In addition, the shaking damage to contents increases higher up in buildings, particularly in flexible steel-frame buildings.

• Fault rupture, or surface rupture, commonly occurs during earthquakes in California because the earthquakes originate relatively near the earth's surface. The ground surface ruptures, or breaks, as the ground on one side moves relative to the ground on the other side. The displacement can be vertical, horizontal, or a combination of both and may be only a few inches or several feet. Any buildings or pipelines built across the fault trace will almost certainly be deformed or destroyed. While California's Alquist-Priolo Fault Special Studies Zones Act prevents buildings for human occupancy from being constructed across an active fault, buildings built prior to the Act's passage in the early 1970s, as well as pipelines, rail lines, or roads, are exempt. These infrastructure lifelines must cross faults in California or our principal urban areas would not function.

• Liquefaction is a process in which loose water-saturated sands and other granular materials suddenly lose strength when shaken. The lurching and sliding that occurs can cause severe damage to structures built upon, or pipelines constructed within, those deposits. This problem occurred in the Lake Merced area during the Daly City earthquake of 1957, as well as the Oakland approach to the Bay Bridge and the Marina District of San Francisco during the Loma Prieta earthquake of 1989. The susceptibility of materials to liquefaction, as well as the hazard posed by these materials when shaken (particularly to infrastructure) are discussed and mapped in the liquefaction section of this web site.

• Earthquake-triggered landslides can occur in hillside areas. Because few businesses are located in these areas, the principal impact of these slides will be on roads and pipelines.

• Tsunamis (great waves often called "tidal" waves that originate in the ocean and have nothing to do with the tides) and seiches (waves that originate in closed or semi-closed bodies of water such as reservoirs) are a potential threat to low-lying waterfront areas, particularly facing the Pacific Ocean rather than in San Francisco Bay. Seaside shopping areas, marinas, and port areas are the most vulnerable. More information on this hazard is contained in the tsunami section of this web site.

Photo courtesy of Degenkolb Assoc.

1. building structural failures.

2. dislodging of asbestos or encapsulated asbestos.

3. underground pipeline breaks due to soil movement.
   

4. above-ground pipeline breaks due to:
   1. breaks in short connector pipes due to differential movement between pipes and structures.
   2. impact from other structures or
      equipment.
   3. damage from failing pipe supports.

5. cylindrical storage tank failures due to "elephant's foot"
   buckling, weakening from corrosion, or sloshing of contents.

6. toppling of elevated tanks.

7. shifting and overturning of horizontal tanks;

8. sloshing from open-topped tanks.

9. industrial equipment problems due to sliding or overturning,
   or internal failures.

10. falling containers and shelves, particularly in:
    1. hospital, school or business laboratories; or
    2. liquor, drug or grocery stores.

1. breakdowns in utilities, including communications, water, and power.

2. people not following established procedures or not using restraining devices.

3. malfunctions of control or alarm systems.

4. shortages of emergency and clean-up personnel.

5. disruptions of transportation supply/distribution systems.

6. indirect impacts due to damage to raw material suppliers or equipment suppliers.

Hazardous Materials Problems During Earthquakes: A Guide to Their Cause and Mitigation.

The research on which the Guide is based included an examination of records of hazardous materials problems collected by others, as well as ABAG staff interviews with a number of local governments and private businesses with first-hand experiences in the Coalinga, Livermore, Loma Prieta, and Whittier earthquakes in California.

A companion document subtitled Background Materials contains checklists and guidelines, general articles by other researchers, samples of company and local government programs, liability and regulatory background information, and extensive lists of other references. In addition, a database of known hazardous material releases in 29 past earthquakes is available.

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The principal objective of this ABAG project was to help those responsible for business and government programs relating to hazardous materials or earthquakes do a better job of mitigating some of these joint problems. We can learn from the past and we can learn from each other. The project was initiated before the Loma Prieta earthquake in October 1989. That earthquake confirmed earlier conclusions, yet provided additional information on what types of mitigation measures tend to work, and what types tend to be nothing but "false friends."