Guide
What to qualify in a US contract blender
Updated
Blenders differ far more in what they can practically run than in what they claim to be able to run. Four checks separate them.
Vessel size against your batch
A plant whose smallest vessel is much larger than your batch will either refuse the work or run it inefficiently and price accordingly. A plant whose largest vessel is much smaller cannot scale with you.
Ask for the vessel list with working volumes, and match it to your batch now and in two years.
Changeover and cross-contamination
Ask what runs on the same equipment before and after your product, what the cleaning validation looks like, and how changeover loss is calculated.
For anything sensitive to contamination this is the question that decides suitability, and it is answered by process documentation rather than by reassurance.
Testing capability
What can they test on site, what goes to a third party, and what is on your certificate of analysis? A blender who tests only what is convenient is leaving the specification partly unverified.
Agree the certificate of analysis parameters before the first batch, not after a disagreement about one.
Regulatory posture
Chemical substances in US commerce sit under an EPA inventory regime, and food and supplement products under FDA guidance. Which applies to yours depends on the substance and its use.
Ask which regimes they operate under, what they file and what they expect you to file. A blender with a clear answer has done it before; one who defers entirely to you may not have.