Safety-seeking behavior is defined as an action with in a feared situation that is performed with the aim of preventing harm and reducing anxiety. So all types of escape from a particular situation, as well as neutralizing and performing compulsions, are forms of safety-seeking behavior. They are all ways of responding to an obsession.
A message we will return to over and over agin is that safety-seeking behaviors maintain obsessions. They prevent you from testing out your fears, allow the obsession to persist, and make the problem worse in the long term. Safety-seeking behaviors are a way of 'trying too hard', to prevent bad things happening; but they do not work, because the solutions then become the problem.
Our earliest understanding about OCD was based on learning theory, and the effect of avoidance and compulsions on fear. Put simply, each time you avoid a situation or activity the behavior is reinforced because you have prevented yourself from experiencing anxiety and the harm that you think might have occured if you hadn't avoided the situation. This 'reinforcing' means that you are more likely to act in the same way when you next have the oppurtunity of avoiding a situation. For example, if you avoid using public toilets because of the fear of contamination, you will have prevented yourself from feeling anxious and so you will go on avoiding public toilets because then you won't feel anxious because you think you will see blood, then you will do the same thing the next time. In both cases the avoidance behavior is reinforced.
A second key issue is the way you respond to the anxiety and the belief that you can prevent harm. In OCD, a common response to anxiety is a ritual or safety-seeking behavior. Rituals are also reinforced, so that when, for example, you check that a light switch is off and then feel less anxious, you are more likely to act in the same way in the future.
In short, avoidance and compulsions seem at first to 'work'! They work in the sense that you think that you have prevented harm (e.g. your electrics do not catch fire) and this usually either reduces your anxious or stops you feeling anxious. Unfortunately, avoidance and compulsions have a high cost, and in the long term they make you more anxious and fearful.They feed the obsesion. Thus trying too hard to get rid of your intrusive thoughts and feelings by avoidance and compulsions actually becomes the problem.
Exposure also allows you to find out whether what you expect to happen does in fact happen, and to learn new ways of behaving by acting against the way you feel. You can do a kind of formal 'behavioral experiments', in which you test out some of your feared sequences (e.g. belief that when you are very anxious you will lose control and go crazy). During the experiment, you will see if there is another way of looking at being anxious that would allow you to act differently. In some situations of course, you cannot test whether a belief is actually true, because the experiment could last for many years.