Can pesticide-contaminated material contaminate my oil extraction system?

Yes, but only high levels pose a significant risk of contaminating later runs.

Luckily, regular cleaning with most solvents – ethanol, isopropanol, or acetone, or an empty run with extraction solvent – will help to remove any pesticide residue present. Most pesticides are non-volatile, and so will generally not be recovered into your recovery tank during evaporation and purge. It is possible that some CO2 extraction systems may enable some pesticides to be recovered in the recovery tank, but this is only hypothetical and would depend on how your system is designed and how it is operated.

The safest bet is to only buy material you know is clean – with a pesticide residue Certificate of Analysis – and to regularly clean all parts of your extraction system that could contaminate your product.