Perchlorate Basics

What You Need to Know About Perchlorate

What it is, How it's used, and why the minute levels found in the environment pose no threat to human health.

What is Perchlorate?

Perchlorate is a substance with chemical formula ClO4− that consists of one chlorine atom and four oxygen atoms. Perchlorates are often produced by natural processes but are also produced artificially.

How It's Used

Perchlorates have been used for more than 50 years to treat thyroid disorders. They are also used extensively within the pyrotechnics industry. Ammonium perchlorate is a component of solid rocket propellant (not "rocket fuel"). Lithium perchlorate is used in oxygen “candles” on spacecraft, submarines and in other situations where a reliable backup oxygen supply is needed.

Where It's Found

Though perchlorate can be man-made, it is well-documented that perchlorate is also naturally occurring; it is formed atmospherically. Naturally occurring perchlorate has been found in water supplies, soils, arid-region plants, organic farming fertilizers and even on Mars.


Perchlorate has been used for decades in healthcare and industrial capacities, from medical treatments to solid rocket propellant (not "rocket fuel"). During this time, a wide array of institutions and organizations have intensively studied perchlorate and its effects. Learn more about the evolution of the use of perchlorate over the past 60 years.