Difference Between Radiation and Irradiation

Main Difference – Radiation vs. Irradiation

Radiation and irradiation are two terms used to describe processes of transferring energy to and from an object. The main difference between radiation and irradiation is that the term radiation refers to many different processes of transferring energy including the transfer of energy via electromagnetic waves or the emission of particles during nuclear decay, whereas irradiation refers more specifically to the process by which an object may be exposed to radiation.

What is Radiation

Radiation describes several different processes of transferring energy. This includes the transmission of energy in the form of electromagnetic waves or in the form of nuclear radiation (which refers to alpha, beta and gamma radiation).

We can classify radiation into several different “types”. Among these, electromagnetic radiation refers to the transmission of energy via electromagnetic waves (i.e. photons), which have been set up as a result of a motion of charged particles. Nuclear radiation refers to alpha and beta particles or gamma rays produced when unstable nuclei break down to form stable nuclei.

What is Irradiation

Irradiation refers to the process by which an object is exposed to radiation. More often, the term is used to express a deliberate exposure to radiation.

Ionizing radiation refers to types of radiation that can cause ionizations, as it passes through a material. Ionizing radiation includes X-rays and gamma rays in the electromagnetic spectrum, as well as alpha, beta and gamma radiation originating from nuclear decay (gamma radiation emitted during nuclear decay is also the same as the gamma rays we talk about in the electromagnetic spectrum).

Irradiation has numerous uses. Food can be irradiated with ionizing radiation to kill microorganisms on it, allowing the food to be preserved for a longer time. Irradiation does not make the food itself radioactive, although chemical changes can occur in the food when chemical bonds break due to irradiation. However, research into these chemicals has not revealed any harmful effects [1]. To irradiate food, electron beams, X-rays or gamma rays are used.

Difference between Radiation and Irradiation_Radura_Symbol

This Radura symbol is used in the USA to indicate that food has been irradiated.

Killing cancer cells in patients by exposing cancerous cells to ionizing radiation is also a process of irradiation.

Irradiation is also used frequently to sterilize disposable objects such as syringe needles. During this type of irradiation, the object to be sterilized is exposed to ionizing electromagnetic radiation such as x-rays or gamma rays. Electron beams are also used to sterilize objects in some cases.

Difference Between Radiation and Irradiation


Radiation has a broad meaning, covering  different cases of transferring energy, including electromagnetic radiation and nuclear radiation.

Irradiation refers specifically to a process by which an object is exposed to radiation.



  1. Brennand, C. P. (1995, March). Ten Most Commonly Asked Questions About Food Irradiation. Retrieved August 20, 2015, from Idaho State University: http://www.physics.isu.edu/radinf/food.htm

Image Courtesy

“Radura symbol used for irradiated food in USA (as legally implemented)” by Author Unknown (United States Department of Agriculture, Food Safety and Inspection Service. Converted from EPS to SVG for Wikipedia use by en:User:CALTD.) [Public Domain], via Wikimedia Commons

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