Phototoxicity. The neglected factor.

Ignorance of phototoxicity by the general biomedical community constitutes a health hazard. Certain food colorants and dyes proposed for use in angiography produce lethal effects in cells and whole organisms on light exposure but not in the dark. Yet-light-relatedness is usually neglected in toxicity studies. We urge that the specific involvement of light be considered whenever the toxicity of a light-absorbing substance is assessed.