I think you are trying to put too much on one report. An Access report isn't like an Excel workbook where you can make multiple worksheets in one workbook and put anything you want on a given worksheet.
The easiest thing to do would be to make two report objects: Your chemical usage report and your summary report and just print them both separately. However ... it might be possible to use Domain functions (ie DLookup, DSum, DCount, etc.) in the Footer to make your Summary Page if you can get the footer to appear on a separate page. If you have a lot of chemicals though, the latter would be tedious and would not be dynamic. You'd physically have to create one field per chemical.
The best solution is to create two reports and run them separately or run them together in a macro or vba module.