Actinism is the property of
solar radiation that leads to the production of
photochemical and
photobiological effects.
Actinism is derived from the Greek ακτίς, ακτῖνος (a ray or beam). The word
actinism is found, for example, in the terminology of imaging technology (esp. photography), medicine (concerning sunburn), and
chemistry (concerning containers that protect from photo-degradation), and the concept of actinism is applied, for example, in chemical photography and
X-ray imaging.