Fireworks, the Fourth, Perchlorate and the Facts

As a component of fireworks, the chemical perchlorate is often in the news around the Fourth of July. As a compound made up of chlorine and oxygen—and as a medicine once used to treat thyroid disorders—perchlorate is one of the most widely researched compounds in our environment. As a result, there are several important facts about it that can help place comments about perchlorate into correct context.

  • Based on findings from the National Academy of Sciences, environmental levels of perchlorate do not pose a public health concern.
  • No adverse effects from exposure to perchlorate at environmental levels have been shown in more than 60 years of scientific research. Claims that environmental levels of perchlorate have been linked to thyroid problems, cancer, birth defects or other serious human health impacts are inaccurate and unsupported by the wealth of scientific research available on perchlorate.
  • Based on US EPA science and criteria, perchlorate does not meet the characteristics of endocrine disruptors. Most notably, it does not mimic any human hormones, a key characteristic of endocrine disruptors.

Despite the volume of scientific research on perchlorate, it remains a widely misunderstood compound, one that is often confused with other chemicals (such as perchloroethylene—a solvent used in dry cleaning) and one that scientists and regulatory officials are continuing to study.