Following up on yesterday's shutdown of Rep. Raul Grijalva's office after a letter containing a toxic substance was mailed to them, we called up Adam Saravana, Grijalva's communications director, and got the inside story.

Here's what Adam told us:

At about 12:30, as they do every day, the staff checked the mail for the congressional district office. Among the letters was this envelope with -- it just had a mailing label, with a name and address on it, and I can't confirm if it's real or not. Inside the envelope, there were two pieces of paper with swastikas drawn on them. And there was a little plastic baggie with this powder in there. And so they called the police. The police showed up, and then the fire department arrived. And the fire department did a test, and said, 'OK, this is actually toxic. This is for real.' So the congressional office was on lockdown for more than an hour. They first had a police cordon around the building, they wouldn't let the staff leave -- the staff were all there while they were all tested for their vital signs and everything. And finally the fire department got its results back and they said, 'This stuff is dangerous, we need to get you out of here.' So they kept the cordon up but they evacuated the building. Our congressional staff all went home. The congressman and I were out, and so they wouldn't let us in the building.

The substance, he told me, was identified as hydroxyacetenalide:

Symptoms of overexposure to this compound include nausea, vomiting, cyanosis from methemoglobinemia, injury to the liver, kidneys, central nervous system and heart, circulatory collapse, drowsiness, confusion, liver tenderness, low blood pressure, cardiac arrhythmias, jaundice, acute renal failure, death due to liver necrosis, metabolic acidosis, hepatic damage and cirrhosis. Other symptoms include changes in exocrine pancreas, diarrhea, irritability, somnolence, general anesthesia, fever and hepatitis. Diaphoresis and general malaise may occur. Exposure may lead to hematological reactions and, occasionally, skin rashes and other allergic reactions.

It's available generically as Tylenol, but not in mass quantities as a powder (though it certainly is conceivable that the senders simply ground up a large amount of Tylenol to create this). In powder form it can be very dangerous indeed. Not only will breathing it potentially induce these symptoms, but it also happens to be highly combustible.

As KOLD-TV News 13 reported:

This is not the first time the office has been the target of intimidation. In April, the Congressman closed down the Tucson office after receiving personal threats against his life. In July, someone fired gunshots through the front of his Yuma office. Rep. Grijalva calls it an indication of how emotionally charged this political year has been, in light of his stance on Arizona's illegal immigration law. "This is not the way we have a civil debate," said Rep. Grijalva. "This is not the way we make decisions in this country. I think the tone has been ugly." Grijalva's Republican opponent in the race for Arizona's Congressional District 7 seat issued a written statement late Thursday evening. Ruth McClung wrote: "There is no room for hatred or terror in this race. Mr. Grijalva and I have different opinions on a wide range of issues. However, our differences on policy and governance are legitimate and reasonable, and should be allowed to play out within the established boundaries of political discourse."

This is clearly an act of domestic terrorism, and it's astonishing to me that my fellow journalists don't seem to recognize it as a significant escalation of the threats towards Democrats we've seen in recent weeks.

As I noted yesterday: