Sample Integrity Observation #5 Chain of Custody Information Incomplete

Modified on: Mon, 14 Jan, 2019 at 12:41 PM


 The Chain of Custody (COC) provides the lab with a specific set of instructions to follow with respect to analytical methods, parameters, RDLs, holding times and billing instructions.  It is a legal document that should stand up to peer-review and possible legal scrutiny and so accuracy is critical.

Tips for Filling Out the COC:

  • Populate the COC by section
  • Have a COC template for field staff to review before submitting a completed COC
  • Utilize eCOC:
    • Creates templates for consistent and accurate information over multiple submissions
    • Mandatory fields ensures required information is populated


The lab reviews the COC to confirm the required information is available to proceed with the requested analysis.  If any item is unclear, the lab contacts you for confirmation before proceeding.  Some items are critical and will prevent the lab from proceeding until clarification is received (i.e. missing analysis).

Some common tips to remember.

  • Include both the sampling date and the sampling time
  • Sampling date should be before the relinquish date
  • Confirm the matrix listed matches the sample matrix
  • Each sample has a corresponding analysis (or Hold) request checked off
  • eCOC has mandatory fields and built-in smart logic (example:  errors when adding soil tests to a water sample) to assist with accurate COC submissions

Upon receipt of sample submission, chain of custodies are checked for the information listed.

When any of these fields are incomplete or inaccurate information is entered on the COC, a deficiency will be applied.

Currently, if the COC is missing fax number, TAT or IOL contact, a deficiency is not applied.

Note that Contract Affiliate & Contract # and IOL Task Order/Consultant PO number are mandatory fields and will be captured under deficiency #17

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