Both are valid. Perchlorate is a oxidizer and after oxidation no longer exists in its previous state. Perchlorate also can be an oxidation product from chlorides. I've never heard referring to an oxidation product as highly oxidized, only the substance it was oxidized from. Relative potential for oxidation is rated high to low, favoring the original NASA wording

Perchlorate is recognized as an oxidant. The definition of an oxidant is substance that oxidizes another substance; an oxidizing agent. The PAO announcement is overall correct.

Perchlorates are indeed strong oxidizers; so much so that they have been used as the oxidizer in certain older generation solid rocket fuels. Their use has been discouraged for new developments, however.

re: This press release says: "perchlorate, a highly oxidizing substance".

Good catch. We described perchlorate as an oxidant (true, though it's not a particularly aggressive one at low temperature), which was translated to "a highly oxidizing substance" by the writer of the release who has the job of turning our gobbledygook into English. A couple of us proofread the final copy, but missed it.

Mike Hecht

The MSDS for, e.g., sodium perchlorate, describes it as a "strong oxidizer."

http://msds.chem.ox.ac.uk/SO/sodium_perchlorate.html

In full context:

"Unstable. Strong oxidizer. Contact with combustible materials can cause fire. Shock sensitive and potentially explosive. Incompatible with a wide range of materials, including organics and other combustibles, powdered metals, acids, reducing agents. Very hygroscopic. Heat sensitive."

No need to reinvent plain English, or rewrite the MSDS.

Does -anybody- think this percholorate they've found on Mars came from Phoenix's own landing rockets??? It seems like if they want an uncontaminated sample of martian soil they'll need a rover to crawl away from the area of the landing site and -then- take a sample and analyze it.