Periodically, the list of chemicals available in CHEM is updated so you have more ingredients to use in your propellant formulations. The list of propellant ingredients for CHEM Version 3 is in the file “pepcoded2.daf”. The list of chemical ID numbers and their chemical names are in the file “Idnum.txt”. Future updates to these files will be free and available on this page.

Update (March 1, 2025): When you open CHEM and click on the ID number list, the chemical ingredient list may not reflect all the ingredients included with CHEM. To check to see if you have a complete list, open CHEM and click on the ID Number List button. Look for Sorbitol as ingredient 1107. If you have it, then your list is up to date. 

If you do not have it, then you can click on the “Automatic Update Software” button and download the updated software. Unzip the file and run the file “Chem-update-setup.exe”. Chrome will block the download as suspicious because it contains the “Chem-update-setup.exe” file. Click on the Chrome download symbol in the upper right-hand corner and select the option to permit the download.