Something you may or may not have come across on the whole conversation of leak detection methods is Fluorescein Leak Detection Dye (sometimes known as Fluorescent Leak Dye or Fluorescein). In this article, we will explain what fluorescein leak detection dye is, how it works and potential uses to find water leaks.
Importantly, we will look at the downsides of using it, the health and safety considerations and also situations where it should not really be used.
As you can see from the image below, in the top-left image, the fluorescein dye is a pinkish colour when it is dry. However, once it is mixed / diluted into water, it goes a bright yellow / green colour as can be seen on the right in the bottle (other colours are available too). This liquid is what can then be used, in some specific situations, to potentially help locate leaks.
![Fluorescein Leak Dye](https://leakdetection.co.uk/wp-content/uploads/2023/04/Fluorescein-Leak-Dye.jpg)
What is Fluorescein?
Firstly, it is important to point out that ‘Fluorescein’ compounds will vary according to how they are manufactured and the application. For example, there are possible medical uses as well as industrial ones so differences are likely to occur. Each product will have its own ingredients labelled and safety data sheets which you must always read and follow. There are also various derivatives, for different applications.
On the topic of safety, see our other interesting articles:
- Hazard Symbol Meanings
- Fire Classification – 6 Types
- Artex and Textured Coatings
- Biohazard Cleaning Safety
On the Wikipedia Fluorescein page about what it is in more detail. But in a nutshell, it is an organic compound with fluorescent properties. Which makes it stand out visually, especially if used in conjunction with a UV light source (usually a ultraviolet torch in some common uses).
You can see this in an example of fluorescein dye under UV light below:
Something that this is not to be confused with is Leak Detector spray, like the example shown in the picture below. Although they may look similar, they are different and have different applications commonly. Although it is possible that products such as this may include fluorescein, they are most often used to find air leaks (bubbling up).
![Leak Detector Spray](https://leakdetection.co.uk/wp-content/uploads/2023/04/Leak-Detector-Spray.jpg)
How does Fluorescein Leak Detection work?
Clearly, as we have said in previous guides, we have many methods available to help locate water leaks effectively. These include:
- Thermal Imaging Leak Detection
- Thermal Imaging Inspection Cameras
- Borescope Cameras
- Moisture Meters
- A variety of other Leak Detectors
These can be for a variety of water leaks including Water Leak in Concrete Floor or Ceiling Leaks
It is fair to say that many of the other methods are more commonly used than Fluorescein Leak detection, for a number of reasons, but mostly because the other methods are more effective in more applications. However, there are other applications whereby fluorescein leak dye can be beneficial.
Basically, because of what we said earlier about the mixed liquid being highly visible under UV light, it can help you to see water leaks in certain situations which may not be visible easily otherwise. Clearly, ‘normal’ water is clear whereas fluorescein is more vivid to the human eye and even a very small leak could be seen. It can also help to highlight the path of travel for water leaks – which can then lead to spotting areas of water damage.
Clearly the challenge is getting the solution into the places you want to test for leaks, which brings about other issues – for example, using it on a drain or sewer leak might be practical or safe but on other water sources (especially drinking water) may not be straightforward. So next we will look at the possible downsides of fluorescein in leak detection applications.
Fluorescein – Top Tip
Leak Detection Team
“Fluorescein is generally a professional product which should only be used in accordance with the specific application it is intended for, and following the manufacturers instructions and guidance, including the appropriate usage of Personal Protective Equipment (PPE).”
![Trusted Leak Detection](https://leakdetection.co.uk/wp-content/uploads/2022/09/Trusted-Leak-Detection.jpg)
Fluorescein Leak Detection – downsides and risks
Many of the leak detection dyes are labelled as Fluorescein Drain Leak Tracing Dye (or similar) and some manufacturers (again, always check!) say they can be used for drains, guttering. In the vast majority of instances you should avoid using them on tap water supplies because of the risks to drinking water etc. It has been known for companies to suggest food colouring dyes as an alternative.
This brings us on to another downside of fluorescein in that it is somewhat of a ‘crude’ method, suitable for limited situations, especially compared to other methods professionals like us use. We are over-simplifying but, on many occasions (especially with drains etc), it is a case of pouring in the dyed liquid and seeing where you can spot it. And that may not be exactly where the water leak is, just possibly where the water is running to.
Finally, another limitation of fluorescein and leak tracing dyes is that, clearly they can stain materials. This may not be an issue if you are pouring down a drain, but in a house it could discolour the fabric of the building and could be difficult to remove. For example if it leaked onto a painted ceiling, wallpaper etc.
Water Leak Repairs – Areas Covered Locally
We are a local leak detection company, who provide a range of damage management services too, we are based in York and provide leak detection, including ultrasonic water leak detection in the following locations:
- Leak Detection York
- Leak Detection North Yorkshire
- Leak Detection Yorkshire Coast
- Leak Detection East Yorkshire
- Leak Detection South Yorkshire
- Leak Detection Teesside
If you have a water leak contact our local friendly and experienced team for help.
![Fluorescein Rainbow Restoration](https://leakdetection.co.uk/wp-content/uploads/2023/04/Fluorescein-Rainbow-Restoration-Logo.jpg)
![Rainbow Restoration Leak Detection](https://leakdetection.co.uk/wp-content/uploads/2023/04/Signature-logo.png)
Is fluorescein dye safe?
![Leak Detection Logo - Small](https://leakdetection.co.uk/wp-content/uploads/2021/12/Leak-Detection-Logo-Square-2-150x150.jpg)
Fluorescein dyes have multiple applications from drain leak detection through to some medical applications and so the contents will vary for each one. Each of them will have their own safety data sheets, instructions for when and how they can be used and safety warnings too which must be strictly followed, carefully and professionally. If in any doubt whatsoever, do not use it and get professional help as it is generally a professional product.
What is the dye used in leak detection?
![Leak Detection Logo - Small](https://leakdetection.co.uk/wp-content/uploads/2021/12/Leak-Detection-Logo-Square-2-150x150.jpg)
There are a wide variety of different dyes used in leak detection, mostly for drainage leaks. Consequently, the exact type of dye used will vary. However, one commonly used drainage leak dye is ‘Fluorescein’ which is a fluorescent dye. In other applications, other dyes may be used, including possibly food colouring dye in some instances. Always take care, get professional help and follow instructions and safety data sheet guides for whatever dye is used.
At Rainbow Restoration – York & Yorkshire Coast we are local Leak Detection Specialists, including business water leaks, so if you need help finding a water leak or getting your home or business back to normal after a water damage or a flood, get in touch with our friendly, experienced local team who will be happy to help with this. We are based in York.