The IDDSI flow test is a simple, inexpensive method developed by Dr. Ben Hanson and the IDDSI board members, to accurately and reliably determine the thickness level of liquids used for helping individuals with dysphagia.  In order to obtain accurate results the correct type of 10 ml syringe must be used.  

The flow test is designed to measure the flow of liquids to accurately identify the thickness level of the liquid based on what fluid is left in the 10 ml syringe after 10 seconds.  The test works best for IDDSI Levels 0-3.   

Since level 4 liquids do not flow, it is more appropriate, convenient and accurate to use the fork-drip and spoon-tilt tests in order to identify whether a product is level 4. These testing methods were outlined in the original framework documents.  

All 10 ml syringes are not created equal!

The dimensions of 10 ml syringes differs between manufacturers around the world, therefore IDDSI has specified the exact dimensions and features of the 10 ml syringe that must be used in order to obtain an accurate result. 

Before using the syringe, check the nozzle is clear and free from any plastic residue or manufacturing defects which very occasionally occur. (See image at right).

To check this, run 10 mls of regular water through the syringe.  It should take about 7 seconds for it to completely run through.