Part of the problem with Oppau was that they were dynamiting a 50/50 mixture of ammonium nitrate and ammonium sulfate, which they thought was safe. It turned ou

Part of the problem with Oppau was that they were dynamiting a 50/50 mixture of ammonium nitrate and ammonium sulfate, which they thought was safe. It turned out that dynamiting such a mixture isn't safe after all. https://blogs.sciencemag.org/pipeline/archives/2017/03/03/how-not-to-do-it-breaking-up-ammonium-nitrate https://blogs.sciencemag.org/pipeline/archives/2017/03/03/ho... As always, safety regulations are written in blood.