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Fluorescein Dye

Fluorescein Dye

Fluorescein, C20H12O5, is an organic dye which when dissolved becomes extremely fluorescent under UV light. This dye is used in leak detecting and fluid tracing, as well as in highlighting markers and fluorescent toys. In small quantities it is non-toxic, and is even used to find micro fissures in eye surgery, however our products are not food-safe and should never be used in contact with skin or internally. 

All dyes have manufacturer certification and SDS available on request, excepting the craft-grade dye, which shouldn't be used in expensive, critical, or food-grade machinery, but is cheap and plenty effective if you're just looking to have fun or track non-critical water based systems.

  • FAQ

    Q:Which dye do I need?

    A: Depends on the fluid you're dying! Our polar solvent dye can be used with any polar solvent, such as water or glycol solutions. Our non-polar solvent dye can be used with most oils and fuels. For A/C dyes, see below.

    Q:Why isn't it glowing? It looks red, not green!

    A:The dye loses it's fluorescent properties at high concentration, which is how we sell it in order to be effectively packaged. Once it's dissolved in a larger quantity of fluid, it will turn green.


    Q:How much dye do I need?

    A:Recommended concentration for oil and water dyes is 16 drops per gallon of fluid to be dyed, so the 6cc bottles can dye up to 8 gallons, the 15cc bottles up to 20 gallons.


    Q:Will this dye work with my A/C system?


    A:Our A/C dyes are immersed in a PAG100 lubricant type, which is common, but not universal. You need to research your specific system to make sure this lubricant type is compatible. If you are unsure, or aren't very familiar with refrigeration systems, don't take chances! These systems can be very hazardous to repair, and contain chemicals that are toxic and environmentally hazardous. Be safe!

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