Good point Paul. I emailed Prochem and this is the reply:
"Yes, you are right to ask as there have been some changes since 2007. In fact we no longer issue the Chemical Compatibility Chart and the general rule of thumb is NOT to mix chemicals unless specifically mentioned that you can do so on the labels. For example, additives such as Citra-Boost or Odour Neutraliser can be mixed with pre-sprays and extraction detergents as mentioned on the label. One mix that we no longer advocate is Clensan with Fibre & Fabric or Crystal Green. Clensan should now be used on its own and never mixed with other chemicals.
Sometimes it is possible to use one chemical OVER another. For example when you put down Stain Pro you can then spray Fibre & Fabric Rinse on top of it to neutralise.
If in doubt you can consult product labels on our web site. here is the link:
http://www.prochem.co.uk/safety_data_sheets.htm If you don't find the label instructions on the Safety Data Sheet then it will be on the Product Specification Sheet as we are in the process of changing all the SDSs to a new format to meet industry requirements.
Thank you for mentioning that to me. I will try to get a note added to the Cleaning Specialist page about Chemical Compatibility."