Risks and Hazards share a very confusing relationship as they are thought to be same by many hence they are used interchangeably. Bit practically, Risks and Hazards are quite different from each other. While a Hazard is defined as the potential for harm to people, property, or the environment; a risk is defined as an estimate of the probability of a hazards-related incident or exposure occurring and the severity of harm or damage that could result (Manuele, p. 111, 2004)
The definitions quite clearly and vividly the difference between these two terms.
In simpler terms while Hazard is a potential danger, risk measures the possibility of how much and how much can the hazard actually harm. Unlike hazard, risk takes into account various factors like the likeliness of exposure to a hazard, frequency or tendency of exposure to a hazard etc. Thus risk forms a broader term, which inherently includes hazard, as its part while the reverse may not be true. A hazard does not mean that you are at risk necessarily or compulsorily. It is something that could harm but risk gauges its potential of harming in true sense.
In a very general sense,
Risk= Exposure * Hazard
There are various kinds of hazards one comes across in a workplace and each of these hazards have their associated potential risks. E.g. manual handling of tools like knives, secateurs, weed bags, mattocks etc. or lifting of heavy tools or items incorrectly is a hazard and the potential risk from this hazard is back injuries, strains, and cuts. Now the risk would in turn depend on the exposure to the hazard i.e. if a person does this once or twice it might or might not lead to the associated risks but if it is done more than once then the chances or probability of risks increases. This clearly shows that risks are directly proportional to the amount of exposure to the hazards.
Another simple example that could establish the difference between these two terms is of a wet floor. Wet floor in itself is a hazard; it could be risky and result in risks like slips, falls and resultantly in injuries. But again this depends on the exposure to the hazard. If nobody visits the part of floor that is wet it would not be risky but if large number of people visit it, the risk increases directly and resultantly this hazard could result in a disaster.
Though risks are born out of hazards, there are cases at times when we recognize a risk before recognizing the accompanying hazard. These are particularly the cases the likelihood of a hazard turning into a risk is miniscule or very less. E.g. using staircases is a day-to-day activity, but there are chances that a person might fall of them while using and in the process getting injured, but the chances of this happening are extremely remote. In such cases only when someone falls and is injured do we realize that stairs could be a hazard too. Since the probability of someone falling off the stairs is very small, we fail to apprehend the hazard in advance. This clearly goes on to show that even though hazards are central to risks, there might be cases where we recognize the risks first but the hazard later.
Manuele, A. Fred (2008). Advanced Safety Management Focusing on Z10 and Serious Injury
Prevention. New York, NY: John Wiley & Sons Inc.