The use of the rhodamine B as fluorescent tracer in hydrology ask the question of its possible toxic effects in the environment. This study aspire to specify and to complete the results of the former works by the successive examinations of the activity of the rhodamine B in regard to the "daphnies test", its DL50 on the rat and on the mouse, and its cutaneous tolerance. The obtained results confirm the former remarks and express that the solutions of the rhodamine B show any more immediate risks as soon as they appear no more coloured (higher dilutions 1.10(-7)). However it remains to evaluate its long-term carcenogenic activity.
