Thanks to its detection sensitivity and its very low uptake, fluorescein is commonly used in the field of hydrology. For instance, fluorescein is used for groundwater flows mapping; for hydraulic connexions monitoring; for flow time studies; river downstream measurements; seepage water pattern studies; waterproofing layers monitoring; spreading of liquid substances simulation etc.
Fluorescein also allows to conduct various pipe networks diagnostics. Its use is not limited to the hydrological and diagnostic fields. Its scope of application is much larger as it is also used for leak detection and colorimetric point of reference in the field of maritime safety; for chemical products colouring and maintenance; for industrial penetrant testing; for behavioural studies of insects and animals in the medical field; for aquatic decoration or even for expert-assessment damages.