: This safety guide describes the explosion hazards and the safe handling methods of hydroxylamines that were revealed within the process of the investigation and the research about the explosion disaster in a chemical plant to contribute to the prevention of the same kind of disasters, and has been published as a safety guide of the National Institute of Industrial Safety, an Independent Administrative Institution. It is made up from the following sections;
    In the chapter 1, we describe general matters, the physical and chemical properties, and the reactivity of hydroxylamine, hydroxylamine salt, and their aqueous solutions (hereafter described as "hydroxylamine and the like"), according to literatures, and technical documents from Nissin Chemical Co. Ltd., which was the major manufacturer of hydroxylamine aqueous solutions.
    In the chapter 2, we describe the explosion hazards of hydroxylamine and the like. To evaluate them, we performed a thermal analysis using a differential scanning calorimeter (DSC) and a pressure vessel test of hydroxylamine, hydroxylamine salt, and their aqueous solutions in various concentrations, then indicated the result of the test conclusion according to the evaluation criteria of the Fire Prevention Law.

As hydroxylamine and the like decompose vigorously when metal ion exists, we then indicate the decomposition (ignition) characteristics of the hydroxylamine aqueous solutions and the results of the thermal analysis using a small scale reaction calorimeter (Omnical SuperCRC) with iron ion additive as a representative.

To investigate the characteristics of the detonation of hydroxylamine aqueous solutions, we performed steel tube tests and detonation transition tests within stainless steel pipe with iron ion additive, and indicate the results.

    In the chapter 3, we describe the safe handling method of hydroxylamine and the like, including first-aid treatment, emergency measures, and the related laws and regulations, based upon the literatures and the test results in chapter 2.
    In the chapter 4, as reference materials, we indicate the actually measured properties (viscosity, specific gravity), the test methods for hazard evaluation applied to hydroxylamine and the like according to Fire Prevention Law and evaluation criteria, and examples of disasters caused by hydroxylamine and the like.