Injury is a sequence of events. If all the factors contributing to injury synergise each other or exist simultaneously, then the injury will occur. The injury can be in the form of accident or near-hit (near-missed) incident.
There are two important contributing factors namely UNSAFE ACT and UNSAFE condition. UNSAFE ACT is the act of human that can cause injury such as driving and using handphone at the same time. It can be classified as the person factors. Why that person doing that Unsafe Act? It depends on a lot of factors such as knowledge, skill,attitude and behaviour. UNSAFE conditions on the other hand, are any pre-existence condition which can jeopardise the safety and health such as damage road, smooth floor etc. UNSAFE conditions usually classified as Environmental factors.