ISO 16232-8:2007 describes a method for determining the nature of contaminant particles by identifying their elemental chemical composition using energy dispersive X-ray spectroscopy (EDX) in combination with a scanning electron microscope (SEM). The contaminant particles are extracted from automotive parts or components and deposited on the surface of a membrane filter. In addition to the number and size of particles as described in ISO 16232-7, this measurement gives the elemental composition of the particles analysed.