BOB HIRSHON (host):
Spraying for explosives. I’m Bob Hirshon and this is Science Update.
A new chemical spray could literally catch terrorists red-handed. It was developed by forensic chemist Joseph Almog at the Hebrew University of Jerusalem in Israel. The non-toxic spray turns blood red when it touches urea nitrate. That’s a common ingredient in many homemade bombs, including the one used in the first World Trade Center bombing in 1993.
JOSEPH ALMOG (Hebrew University, Jerusalem):
Under laboratory conditions, we’ve been able to detect a few micrograms of urea nitrate; this is an amount that you hardly see.
Since urea nitrate looks like sugar or salt to the naked eye, the test could be invaluable to anti-terror agents. Almog has also developed other colorful chemical detectors; one of them turns purple on contact with iron residues, indicating a suspect might recently have held a weapon. I’m Bob Hirshon, for AAAS, the science society.