The maker of an explosive linked to bombs in New York and New Jersey over the weekend said on Tuesday there was no proof its Tannerite product had been used in the attacks and said it would be a poor choice for a bomb.
Tannerite, an explosive powder commonly used at gun ranges to make targets blow up, or a similar substance was one ingredient in the homemade bombs that exploded in Manhattan's Chelsea neighborhood, wounding 29 people, and in Elizabeth, New Jersey, according to law enforcement officials involved in the investigation.
Tannerite Sports LLC, based in Oregon, said its product is designed only to explode when struck by a speeding bullet and would not be a good material for use in a detonated bomb.
"It's disgusting that the media spews out a brand name with no proof or thought," company founder Dan Tanner said in an email to Reuters.
Law enforcement officials said they did not immediately know if the bombs used Tannerite, one of its competitors or a homemade version with the same two ingredients, ammonium nitrate and aluminum powder. Some media have named the explosive as Tannerite.
Exploding powders are not regulated by the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives because they are generally sold in a kit with the two ingredients separated. The ingredients on their own do not explode.
Ahmad Khan Rahami, 28, is suspected in the weekend bombings, including Saturday's blast in Chelsea, another bomb found in Chelsea that did not detonate, the bomb found in Elizabeth, New Jersey, and a bomb that went off Saturday morning in Seaside Park, New Jersey. U.S. authorities were investigating whether he had accomplices or was radicalized during trips to Afghanistan and Pakistan.
A Tannerite company expert said the product would make a poor ingredient for a bomb because it is meant to explode only at target practice.
"You have to shoot it," corporate investigator Steve Yerger said in a phone interview. "We certainly would want to know if someone's found a way to ignite Tannerite without a high-powered rifle."
There were no reports that a firearm was used in the New York or New Jersey bombings.
The remnants of the bombs that exploded in Chelsea and Elizabeth were examined at the FBI lab in Quantico, Virginia, two U.S. officials participating in the investigation said.
The lab determined the detonator was the compound hexamethylene triperoxide diamine, or HMTD, which one official said is a poor choice because it is relatively unstable and sensitive to heat and shock.
The explosive was a combination of ammonium nitrate and aluminum powder, said the officials, who agreed that the substance is very difficult to ignite.
Tannerite has tested its product many times but never combined it with HMTD and did not know what the result would be, Yerger said. Adding Tannerite to HMTD would make no sense, he said, because HMTD is a more powerful explosive.
It was not immediately known where the bomb maker obtained the explosives, although Tannerite is easily available in most of the United States.
The bombs included pipe bombs and pressure-cooker bombs similar to those used in the April 2013 Boston Marathon bombing, which killed three and injured 260. The Boston bombs were backed with black powder from commercially manufactured fireworks, a lower-powered explosive.
Tannerite is usually mixed at a firing range, creating a target that will explode and give gun owners instant feedback on their marksmanship.
The materials can be mixed in large quantities, and videos proliferate online of people using the powder and a gun to blow up vehicles, live hogs and other targets.
Exploding targets have been banned in some U.S. national forests, out of fear they contribute to wildfires and are a threat to public safety.
Last year, Tanner told firearms website Guns.com: "No terrorist has used Tannerite to harm anyone, because the unique properties of the product simply does not lend itself to such use."
Homemade bombs are often backed with nails, BB pellets or other small metal objects that serve as shrapnel, increasing their deadliness.
Yerger contended that blaming his company if its product was used in a bomb was akin to blaming a nail manufacturer.
"Are you going to ban nails?" he asked.