Chain of Custody

Chain-of-Custody of Urine Samples
Starting at the time of collection, a sample’s chain-of-custody must be documented and protected. Chain-of-custody is a legal term that refers to the ability to trace and safeguard the sample, from the time it was donated, through the collection, and analysis, of the sample, to the reporting of the result. Chain-of-custody documentation answers the question: Were the specimen and the reported result correctly matched? Sound procedure requires that the sample be secured in a manner that ensures any tampering or attempted tampering is evident. It further requires that each time the sample changes hands or is moved from one place to another, it is signed for and kept in a secure area to ensure against inadvertent or intentional switching with another sample.

Elements of Chain-of-Custody Procedure
The elements of a good chain-of-custody procedure include the following:

  • The donor should be supervised either directly or indirectly while delivering the specimen.
  • The specimen container should be handed directly to the person supervising the collection and labeled and sealed immediately.
  • The collector and the donor should initial the bottle to indicate that both agree that the bottle contains the donor’s urine specimen.
  • The name of each person who has access to the specimen should be noted on a form accompanying the specimen. (Access to the specimen should be limited as much as possible.)
  • The sample should be kept in a secure place, such as a locked room or refrigerator, until it is either tested or sent to the laboratory.
  • Testing performed on-site should be done in a secure location to avoid the possibility of exchanging samples with a passerby.
  • If the specimen must be transported to an outside laboratory, it should be mailed in a sealed container and placed in an external carton with an evidence seal. Government mail or licensed and bonded courier services are acceptable means of transporting specimens.
  • The specimen must be properly labeled so that laboratory personnel will not confuse it with others.
  • If the specimen is to be offered as evidence in a legal proceeding, it must be in the same condition as it was when taken—unless the change is for a justifiable purpose, such as alteration required for the testing procedure.


Q. What is chain of custody (COC)? 
A: A legal term that refers to the ability to guarantee the identification and integrity of samples from collection through reporting of test results. To ensure chain of custody samples must be collected in a manner that maintains the integrity of the sample. This entails filling out appropriate forms, using tamper proof seals and bags, and tracking the sample throughout the whole process from collection to reporting. This produces a specimen that will withstand legal scrutiny.

Q: When is chain of custody used?
A: Workplace Drug & Alcohol Testing

  • Pre-employment
  • Random
  • Reasonable Suspicion
  • Return to Duty
  • Post-Accident
  • Probation & Welfare
  • Order of the Courts
  • Medico-Legal

Q: Does the donor need to consent to testing?
A: Each donor must consent to testing prior to any sample collection proceeding

Q:Who must initial the tamper proof seal?
A: The donor

Q: Who may serve as a collector?
A: A drug & alcohol professional or a trained collector

Q: What should I do if a sample yields negative results?
A: Specimens yielding Negative results will be discarded appropriately by the laboratory

Q: What should I do If a sample yields ‘non-negative’ result?
A: It will be confirmed by Laboratory using extra tests

Q: Is there a protocol for referring a COC sample for confirmation testing? 
Yes. procedures are in place at Laboratory to do this.

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