Perchloric acid (HClO4) in its 70% concentration form is another highly corrosive and reactive chemical. It shares similar properties and uses with the 60% concentration but is even more concentrated and therefore more potent. Like its 60% counterpart, 70% perchloric acid is employed primarily in laboratory settings for specific analytical and synthetic purposes.

In analytical chemistry, 70% perchloric acid can be used to digest samples for trace metal analysis, especially when dealing with challenging matrices. It is also employed for the preparation of perchlorate salts and as a dehydrating agent in various organic syntheses. Due to its extreme reactivity and potential hazards, handling and storage procedures for this acid must strictly follow safety guidelines and be conducted in a controlled environment. Protective equipment, such as gloves, goggles, and fume hoods, is essential when working with perchloric acid to minimize the associated risks.