Hazard

A hazard is a potential source of harm. Substances, events, or circumstances can constitute hazards when their nature would allow them, even just theoretically, to cause damage to health, life, property, or any other interest of value. The probability of that harm being realized in a specific incident, combined with the magnitude of potential harm, make up its risk, a term often used synonymously in colloquial speech.

Hazards can be classified in several ways. They can be classified as natural, anthropogenic, technological, or any combination, such as in the case of the natural phenomenon of wildfire becoming more common due to human-made climate change or more harmful due to changes in building practices. A common theme across many forms of hazards in the presence of stored energy that, when released, can cause damage. The stored energy can occur in many forms: chemical, mechanical, thermal hazards and by the populations that may be affected and the severity of the associated risk.

For example, natural hazards may be defined as "extreme events that originate in the biosphere, hydrosphere, lithosphere or atmosphere"^[1] or "a potential threat to humans and their welfare"^[2] which include earthquake, landslide, hurricane and tsunamis. Technological and human-made hazards include explosions, the release of toxic materials, episodes of severe contamination, structural collapses, and transportation, construction and manufacturing accidents etc.