Effects of certain food dyes on chromosomes of Allium cepa.

The effects of 4 permitted food dyes, i.e., fast green FCF, indigo carmine, orange G and tartrazine, and the non-permitted dye metanil yellow on chromosomes of Allium cepa are reported. A significant increase in polyploid cells was observed in all cases. High doses of these dyes induced chromosome breaks and micronucleus formation. Although all dyes produced mitotic aberrations, metanil yellow and fast green FCF showed comparatively stronger clastogenic activity.