Unfortunately we have been made aware of a quantity of fake 5 Litre Elsan Blue that has been sold at exhibitions and shows.
The easiest way to spot the fake product is that it is a 5 Litre bottle and Elsan does not make a 5 litre size.
If you see this 5 Litre bottle for sale it would be helpful if you could contact the event organiser or your local Trading Standards office and let them know the details of the vendor and where you saw the product being sold.
As this is a counterfeit scam the contents of the bottle are obviously not suitable for treating a chemical toilet. We also do not yet know if there are any adverse side effects on the components of the toilet or health risks to the user.