Usage of 安2013年09月22日 10:18

The kanji 安 is the base of Hiragana あ.
In exact, 安 is pronounced as AN, except some examption as 安室奈美恵(Amuro Namie, A Japanese songer's name).

Basic meaning of 安 is safe as 安全(ANZEN) , safety or perfectly safe 安心(ANSHIN) , secured or relieved as you are in safe.

We say 安心する。 while we cannot say 安全する。
The differencs is infered as follows.
In 安心、 心 stands for heart, a concrete oject, while 全 means just perfect, not a object. 安心 composes of the verb "rest" and "heart", while 安全 does not contain any verbal meanings.

In the nuclear fields, they sometimes discuss the difference of 安全 and 安心 for seeking the level of secure or meaning. But, I think, they are in different categoly of Japanes words.