A mutagen (Latin, roughly change maker) is an agent that changes the genetic information (usually DNA) of an organism and thus increases the number of mutations above the natural background level. Mutagens can be chemical compounds or radiation.
There are several methods to detect how mutagenic an agent is:
... Portrait Gallery
Natural History Museum[?]
Science Museum
Tate Gallery: Tate Britain and Tate Modern
Victoria and Albert Museum
Merseyside
Customs & Excise ...