Ammonium Nitrate Bombs

The right-wing terrorist attack, probably by a lone wolf or very small group of conspirators, in Norway last Friday sounds very similar to the attack in Oklahoma City in 1995. The most common denominator between the two attacks was the use of a large improvised explosive device based upon ammonium nitrate. The use of ammonium nitrate, a common fertilizer used on farms around the world, as an explosive, by terrorists of all political persuasions is very common because it is widely available and extremely easy to use.

News reports about the Oslo attack indicate that European Union rules about registering the sales of ammonium nitrate fertilizer did flag the sale of the material used to make that bomb. That did, apparently, result in Breivik, the apparent mastermind of the attack, being placed on a law enforcement watch list. Since he was a farmer, it appears that no subsequent detailed investigation of his background was done.

Currently the US does not even have rules in place (some state rules exist) that would ensure that similar sales of ammonium nitrate are reported to authorities. DHS has been required by Congress to have such rules in place since 2008, but the notice of proposed rulemaking has yet to be published. That NPRM was approved by OMB earlier this month so we are expecting to see it published any day now.

It is clear that, even if the final rule authorized by Congress were currently in place in the United States, a homegrown lone-wolf extremist like Breivik would be able to buy significant quantities of ammonium nitrate fertilizer. A farmer will be required to register with DHS and some sort of background check will be required, but an extremist that has not come to the specific attention of the government and that has an apparent legitimate use for the material will be able to register and buy whatever quantities they desire.

This is one of the inherent security issues that an open society is going to have to deal with. There are any number of chemicals that can be used to make improvised explosive devices. Even common household cleaning agents can be used to make bombs or chemical weapons. There is no way that a free society can prevent the misuse of all of these chemicals.

Having said that, a chemical that can have massive effect when misused, like ammonium nitrate, do have to have some sort of controls in place to keep that misuse to a minimum. In most cases the requirement for registering with the Federal government to be able to buy ammonium nitrate will have a chilling effect on illegitimate users. It will be a relatively minor inconvenience to legitimate users that will cause some to switch to alternative chemicals (many of which are also able to be used for making improvised explosive devices; that is the nature of nitrogen fertilizers).

But, the American public and their politicians must realize that, even with registration requirements in place, there is a very real chance that a Breivik or McVey will be able to buy ammonium nitrate and construct a bomb of catastrophic proportions. More importantly, ammonium nitrate is just one of a large number of chemicals that can be used to construct similar devices. In a free society that is just one of the risks that we are going to have to live with.