It means they carry sufficient energy to detach electrons from atoms or molecules thereby ionising them.
no
Some of the sun's rays are ionizing and some not. The portion that is not ionizing is the visible spectrum, anything with longer wavelength (infrared), and a bit of the ultraviolet spectrum. The shorter wave lengths are all ionizing.
Alpha particles are ionizing radiation because they have a positive charge and can remove electrons from atoms they interact with, causing ionization. This can damage living tissues if exposure is significant.
it does not
heat or light from the sun, microwaves from an oven, X rays from an X-ray tube, and gamma rays from radioactive elements
Microwaves are non-ionizing electromagnetic radiation, which means they do not have enough energy to remove electrons from atoms or molecules. This makes them safer for everyday use compared to ionizing radiation like X-rays or gamma rays.
Smoke detectors
The IR in IRMER stands for Ionising Radiation to which the regulation relates. MRI does not employ Ionising radiation so as far as I am aware the regulation doesn't apply to MRI.
Sterilization by various means such as steam sterilization (autoclave), dry heat (hot air oven), radiation (ionising & non-ionising),chemical methods etc. kills microorganisms.
Energy from the Sun arrives through space as heat and light (and other things) as a form of electromagnetic radiation. There are two types of this, ionising and non-ionising. Below about ultra violet wavelengths the energy is non-ionising, which means it does no harm except possibly heating things up too much. At shorter wavelengths the energy is 'ionising', which means it could produce radiation sickness by altering atoms in the body. That is why too much sunshine occasionally causes skin cancer.
Because it emits ionising radiation
Radioactive elements.