Chain-of-custody errors occur more easily during specimen collection than during the testing process. The donor, if a drug user, may try to tamper with the sample in a number of ways, such as adding liquid or a foreign substance to the sample or substituting a drug-free sample for his/her own. Errors by the collector can range from improperly labeling and securing the specimen bottle to accidentally contaminating the specimen, or confusing it with another specimen.
To overcome these common errors, a specified sample collection site should be set up with the necessary materials, equipment, facilities, and supervision. This is to provide for the collection, security, temporary storage, and shipping or transportation of urine specimens to a drug-testing laboratory.
The collection site should be secure during drug testing. Only authorized personnel should be permitted in the designated collection site when urine specimens are collected or stored.
Sample Collection Materials
These are the materials needed to collect urine specimens:
- Specimen bottles: wide-mouthed, screwcapped, 60–125 mL translucent polyethylene bottles. (Bottles will be filled 1/2 to 2/3 full of urine.) The caps should contain self-sealing, leak-proof liners. These are available through most medical or laboratory supply companies.
- Labels for specimen bottles with spaces to write the donor’s identification number, name of the collector, and the date and time of collection.
- Seals (evidence tape) long enough to cover the top of the cap and run partially down the sides of the bottles. The seal should have to be broken to open a sealed bottle.
- Chain-of-custody forms to accompany each sample bottle. The form should be designed to show who had the specimen and when.
- Boxes, seals, and labels for shipping specimens.
- Refrigerator or freezer if specimens are to be kept longer than a few hours before analysis. This should be locked or kept in a locked room.
An identification label that shows the date; the individual’s specimen number; and any other identifying information required should be placed securely on the bottle. The donor should initial the identification label on the specimen bottle for the purpose of certifying that it is the specimen collected from him/her.
A chain-of-custody form should be used for maintaining control and accountability of each specimen from the point of collection to final disposition of the specimen. Each time a specimen is handled or transferred, every individual in the chain should be identified. Every effort should be made to minimize the number of persons handling specimens.
The chain-of-custody form should have the following information:
- Donor name or ID number
- Collection information
- Date and time sample was collected
– Name of person supervising collection
– Name of person requesting collection
– Name(s) of person(s) with access to sample
– List of medications being taken by donor
– Any comments about the sample
- Laboratory information
– Date and time sample was received
– Name of person receiving sample
– Tests requested
– Name of person reviewing or certifying test results
– Test results—initial test results and confirmation test results with calibrator cutoffs listed
Typically, these forms are pre-printed with the name of the client; the address of the person reviewing the results; and the pre-selected test panel.
The label that is placed on the specimen container must be designed to clearly link the labeled bottle to the chain-of-custody form. It should be non-removable, or at least tamper-evident, so that it cannot be removed, replaced, or altered. A common security feature is to integrate the label into the actual seal, thus making the seal unique. The label can be pre-printed with the identifying number, and provide an area for the donor’s initials (which should be inscribed after the bottle is sealed); the collector’s signature; and the time and date of collection. The bottle should be labeled in the donor’s presence.
Sample Tampering Prevention
To ensure correct identification of the person giving the specimen, and to prevent donors from using a substitute, collectors should always ask the donor to present an identification card with a photo, such as an employee identification card, driver’s license, or national identity card.
It is not uncommon for people who know in advance that they will be donating a sample to carry a container of drug-free urine or liquid substitute (apple juice, colored water, etc.) into the restroom, and substitute this for their own urine specimen. People have also been known to add toilet or tap water to dilute the sample or add adulterants such as bleach, salt, or vinegar in an effort to manipulate the test results.
A decision must be made on how to balance the need to prevent sample tampering by the donor with respect for the donor’s privacy. Direct observation of the donor delivering the sample can be uncomfortable for both the donor and the supervisor. One approach that reduces the chance of tampering, while affording privacy, is to have the person change into a patient’s gown, and leave purses or other articles of clothing outside the restroom while delivering the specimen.
Chances for adulterating the specimen can be further reduced by:
- using a specified toilet facility
- adding a colored cleaning solution to the toilet bowl
- removing the soap from the facility
- making the hot water tap inoperative
The person collecting the sample then only needs to check the color and temperature of the specimen (it should be between 33°C and 36°C) to make sure cold water wasn’t substituted or added. The donor should provide a new urine sample if any of these requirements are not met, or if particulate matter can be seen floating in the urine or settled at the bottom of the cup.
The specimen should be kept in view by both the donor and the person collecting the sample at all times prior to its being sealed and labeled. If the specimen is transferred to a second bottle, the collection-site person should request that the donor observe the transfer of the specimen and the placement of the tamperproof
seal over the bottle cap and down the sides of the bottle.