Risk is a compound measure of the probability and consequences of failure (Figure 11-1). If probability (or expected frequency per unit of exposure) is expressed quantitatively, then risk can be evaluated as the product of the probability and consequence values. If either the probability is zero or consequence non-existent (i.e., zero), then risk becomes zero.

Hazard is defined as a characteristic or a group of characteristics that provide or cause the potential for a loss. Toxicity is an example of such characteristics.

Therefore, by definition, risk can be changed without changing the hazard. However, it may be noted that risk...