The Introduction to the CanadaGAP Food Safety manuals (VI. Iv. Document Retention) states:
For participants on a yearly audit cycle: All sections in the CanadaGAP Food Safety Manual for Fresh Fruits and Vegetables or Greenhouse Product (1-24), forms, receipts, letters of assurance and certificates must be kept for a minimum of two years for audit, recall or other purposes.
For participants on a four-year audit cycle: All manual sections (1-24), forms, receipts, letters of assurance and certificates must be kept for a minimum of four years for audit, recall or other purposes.