Occupational Health Testing Services >> Workplace Drug & Alcohol Testing >> Workplace Drug & Alcohol Testing FAQs

Workplace Drug & Alcohol Testing FAQs

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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

  1. Pre-employment
  2. Random
  3. Reasonable Suspicion
  4. Return to Duty
  5. Post-Accident


  1. Probation & Welfare
  2. Order of the Courts
  3. 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 medical professional or trained collector.

Q: What should I do if a sample yields negative results? 

A: Specimens yielding Negative results may be discarded appropriately along with the Rapid Drug Screen card.


Q: What should I do If a sample yields ‘non-negative’ result? 

A: It should be referred to the lab for confirmatory testing. Both containers must then be sealed using tamper-evident seals (blue & white ABMC seals provided). Collector must fill in the Donor Identification Number (COC Number on form), date and provide a collector signature. Carefully place one seal over the lid of each specimen container and down both sides. The donor must initial both tamper-evident seals, once in place. 

Q: Is there a protocol for referring a COC sample for confirmation testing? 

When referring a COC sample for confirmation testing you must package the labeled aliquot in a tamper-evident plastic bag.