Posted by CMM

The term “fatal” is not used all that often and for good reason. It implies something that is non-correctable or leads to an irreversible error. In the drug testing world, a fatal flaw refers to a non-correctable procedural error that leads to a cancelled test or unacceptable results. Fatal flaws are rare in high quality laboratories with state-of-the-art testing equipment and carefully controlled procedures. However, fatal flaws are much more likely to occur in the workplace and are usually related to careless handling and improper documentation of the specimens. Collection and testing must be carried out in accordance with the Australian Standard AS4308:2006, which includes fulfilling the chain of custody requirements.

The chain of custody in drug testing refers to the paper trail that documents each step of the collection, control, transfer, and analysis of a specimen. A correct process will document the process from the moment the specimen is collected to the final reporting. Everyone involved in the process has a vested interest in its accuracy. The employee wants assurances that the specimen is properly handled so there is no doubt about who supplied it and that the testing results reflect the truth. In the case of urine testing, employees are highly sensitive to the issues of invasion of privacy and feelings the employer is operating from a position of doubt and suspicion rather than trust. It is critical that the drug testing results be accurate and reliable.1

The employer makes critical decisions about human resources based on drug and alcohol testing results; therefore, accuracy is of the utmost importance to avoid false accusations and legal ramifications. Even the testing laboratory reputation is partially dependent on knowing the samples provided are accurately marked and the documentation is correct.

Finally, the employer’s ability to maintain a substance free workplace depends on the accuracy of the chain of custody because workers cannot respect a faulty system, meaning it does not serve as a deterrent to workplace substance use.

Paying Attention to Details

A quality chain of custody relies on the collection site submitting accurate documentation and specimens that have been controlled at all points to remove the possibility of events like specimen contamination or a simple mix-up of names. Fatal flaws cannot be corrected and laboratory testing either cannot be completed or the results are not reliable, meaning the employer has wasted time and money. Even worse, the employee has been subjected to testing that cannot be used, creating ill will between the employee and employer.

Fatal flaws include:

  • Broken security seals on specimen bottles
  • Missing security seals on specimen bottles
  • Specimen bottle seal shows evidence of tampering
  • Specimen ID number on the seal does not match the chain of custody form
  • Indications of a time period during which the specimen was left unattended
  • Printed name and signature of collector are missing on the form
  • There is not enough urine collected (at least 30 mL) for accurate testing
  • Paperwork is incomplete and has missing information
  • Written statement by collector cannot be obtained to remedy a non-fatal flaw

A Best Practice

Attention to detail is important to avoid wasted effort, obtain accurate results, preserve the integrity of the drug and alcohol testing procedures, and maintain good employer-employee relations. The saliva and urine chain of custody forms play an important role in ensuring that the specimen collected is valid and documented and that the results can be used for making good decisions concerning human resources. They represent a best practice in a workplace drug testing program as long as the Australian Standard’s AS/NZ 4308 chain of custody is followed.2


1 Makkai, Toni. (2000). Drug Use Monitoring in Australia (DUMA) - Drug Detection Testing, Research and Public Policy Series, No.25. Retrieved from Australian Institute of Criminology:

2 Ken Pidd, Ann Roche & Michael White. (2011, October). Workplace Drug and Alochol Testing. Retrieved from NCETA and Flinders University:

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