The red NSF dye products are specially formulated versions of Rhodamine WT dye for
convenient use in water tracing and leak detection studies. This bright, fluorescent red dye is
certified by NSF International to ANSI/NSF Standard 60 for use in drinking water. It may be
detected visually, by ultraviolet light and by appropriate fluorometric equipment. Today it is most
often used visually. Visually the dye appears bright pink to red, depending on its concentration and
under ultraviolet light as bright orange.
The dye is resistant to absorption on most suspended mater in fresh and salt water. Compared to
yellow/green dye products it is significantly more resistant to degradation by
sunlight and when used in fluorometry, stands out much more clearly against background
fluorescence.
Above Information from Technical Data Bulletin
Bright Dyes Red 25 pint 106023-01P (ENVIROredi / Bright Dyes Label), Dye Liquid Downloads and Videos can be found here, Additional Dye Products can be found here.