For the budget-conscious terrorist, fertilizer has been the ingredient of choice—because it contains ammonium nitrate, the chemical foundation of many kinds of bombs. Honeywell International—the Morristown, N.J.–based company famous for thermostats—has now patented a blast-free alternative. The company's fertilizer adds in ammonium sulfate, which binds to the ammonium nitrate and makes it unable to burn quickly. In tests, the fertilizer does not detonate even when mixed with diesel or other fuels. What remains to be seen is whether it performs well as plant food; target crops would be those that need both nitrate and sulfate, such as tomatoes, cabbages and potatoes. Honeywell plans to offer the product by the end of 2009. Farmers will likely pay more for the so-called Sulf-N 26 fertilizer, but those who use it will have some assurance that the Department of Homeland Security won't come calling when they buy in bulk.
This article was originally published with the title "Explosive-Free Mix" in Scientific American 299, 6, 44 (December 2008)