NEW YORK - The bomb that exploded in Manhattan on Saturday contained residue of Tannerite, a legal product used primarily for target practice. Tannerite explodes when struck by a bullet from a high-powered rifle so ranges put it on targets as a way to prove a target has been struck.
The brand-name product is defined as a "binary explosive" by the federal Bureau of Alcohol, Tobacco, Firerams and Exposives (ATF). This means it's sold in two inert pieces, said Jimmie Oxley, a chemistry professor at the University of Rhode Island. It is not an explosive until the two parts are mixed, Oxley said.
Even when two separate parts – ammonium nitrate and aluminum powder – are mixed, the compound won't explode until it's hit by the bullet, she said.
Tannerite cannot be set off by a smoldering fuse, an electronic fuse, an electrical current, an open flame, impact with a hammer or even a low-velocity handgun, according to Steve Yerger, a corporate investigator for Tannerite.
It's a very stable product, he said.
A federal law enforcement official who was not authorized to speak publicly about the ongoing investigation confirmed that investigators found Tannerite residue the bomb that exploded in Chelsea, injuring 29 people on Saturday night.
Tannarite makes it easy for shooters at a range to easily determine whether their shot hit its intended target, Yerger said. Tannerite is sold in many sporting goods stores. It's also available on the Tannerite website.
"We feel horrible that Tannerite has been associated with the bombing," Yerger said,
On its Facebook page Monday afternoon, the company said that it was aware of the bombing in New York and the explosive devices found in New Jersey. "The entire staff of Tannerite stands together in the abhorrence and unintended use of all products that are misused for violence and hate," the Facebook post said.
The ATF does not regulate the sale and distribution of the two chemicals used in Tannerite and similar products, even when sold together in binary "kits," the ATF said.
Mixing binary components together constitutes manufacturing explosives, according to the ATF: "Persons manufacturing explosives for their own personal, non-business use only (such as personal target practice) are not required to have a federal explosives license or permit," the ATF said on its website.
"However, when the binary components are combined, the resulting mixture is an explosive material," the ATF warned. The ATF issued an advisory last year, warning that these products are "high explosives and should be treated with caution and in accordance with manufacturer’s instructions."
According to Tannerite, the company's corporate investigator is working to determine whether the product was used in the bombing.
"At this time we are unable to validate the allegations due to it being an ongoing investigation," according to the company's Facebook page.