Mutagens OR Mutagenic Agents - An agent that has the ability to produce mutation is called the mutagen. A mutagen can be a physical agent (e.g. UV, X-rays) or a chemical. Physical mutagens are radiations of fixed specific wavelength and energy.

Some radiations such as X-rays and γ-rays, are capable of causing ionization (release radicals or ions) in matter through which they pass. Radiations are of two types.

1) Non-particulate, e.g. X-rays.
2) Particulate radical, e.g. α, β, γ radiation.