§1. In administering the sacraments in which holy oils must be used, the minister must use oils pressed from olives or other plants and, without prejudice to the prescript of can. 999, n. 2, consecrated or blessed recently by a bishop; he is not to use old oils unless it is necessary.
§2. The pastor is to obtain the holy oils from his own bishop and is to preserve them diligently with proper care.
Source: Code of Canon Law (Vatican.va)