Department of Health Seal

TGM for the Implementation of the Hawai'i State Contingency Plan
Section 11.3
SAMPLE CONTROL AND CHAIN-OF-CUSTODY PROCEDURES

11.3 SAMPLE CONTROL AND CHAIN-OF-CUSTODY PROCEDURES

Sample control and chain-of-custody procedures are extremely important for establishing that sample integrity was maintained from the time of collection through the time of analysis. Sample control procedures include the use of unique sample identifications, and sample labeling requirements. Chain-of-custody procedures include the use of chain-of-custody forms and custody seals.

11.3.1 Sample Identification and Labels

Each sample collected in the field must be provided with a unique sample identification. In general, sample identification may include some or all of the following information:

  • Project number (if samples collected by a consultant)
  • Project location
  • Sample location information (i.e., borehole or monitoring well identification)
  • Depth of sample collection (for subsurface soil samples)
  • Date/Time reference

A date/time reference is recommended if multiple samples are anticipated to be collected over the course of the project (such as during long-term monitoring projects).

Each sample collected in the field must be properly labeled using laboratory supplied (or equivalent) labels completed with indelible ink. The sample labels should contain the following information:

  1. Sample identification number
  2. Sampling date
  3. Sampling time
  4. Type of preservation
  5. Analysis requested
  6. Initials of sampler

Additional sample information should be documented in the field log including, but not limited to, the following:

  • sample collection method (manual sampling, direct push drill rig)
  • type of sample (e.g. Multi-Increment or discrete)
  • significant observations noted during sample collection (petroleum odor or staining in soil, petroleum product or sheen on water surface)
  • a cross reference of primary and replicate QA/QC samples

The peel and stick sample label should be securely affixed to the sample container. The outside of the sample container should be thoroughly cleaned and dried prior to affixing the label. Application of clear plastic adhesive tape over the label on the sample container provides a secondary means of securing the label to the container. Use of an indelible pen to mark the sample identification number on the container is a good backup method that can be used to identify a sample container in the event that it gets separated from the label.

Do not identify or cross-reference QA/QC samples on the sample labels or on the chain-of-custody form (see Section 10 for additional guidance on QA/QC samples).

11.3.2 Chain-of-Custody

Chain-of-custody is the process by which authorized custody of a sample is successively transferred from one person to another by the use of approved procedures and documents. If sample integrity is to be defensible, chain-of-custody procedures are necessary to document handling of samples from procurement through final analysis and disposal.

A sample is considered to be under a person's custody if:

  • The sample is in the person's physical possession.
  • The sample is in view of the person after that person has taken possession.
  • The sample is secured by that person so that no one can tamper with the sample.
  • The sample is secured by that person in an area where access is restricted to authorized personnel.

11.3.2.1 Chain-of-Custody Forms

Chain-of-custody forms are used for tracking the samples from the time of collection in the field through the time of analysis. The chain-of-custody form contains the following information:

  • Project identification
  • Sampler's name
  • Sender - Company name and address
  • Destination - Laboratory name and address
  • Sample identification
  • Number of sample containers per sample
  • Preservation, if any
  • Date and time of sample collection for each sample
  • Requested analyses
  • Special handling requirements, if any
  • Shipping company
  • Printed name and signature of person relinquishing custody, and date and time when custody relinquished
  • Printed name and signature of person receiving custody, and date and time when custody received.

Complete chain-of-custody forms at the time of sample collection and prior to leaving the field site. Analytical laboratories typically provide company-specific chain-of-custody forms, and sample labels, if sample containers are procured through the analytical laboratory. Complete chain-of-custody forms with indelible ink.

When transferring samples, the individuals involved must sign, date, and record the time in the relinquished/received-section on the form. The sampler retains one copy of the chain-of-custody form when relinquishing the samples following sample collection. Completely fill out all applicable sections of the form and numerically sequence the forms (i.e., page 1 of 3, etc.) if more than one chain-of-custody form is used for a sample batch. Consider grouping similar sample media in chain-of-custody batches for submittal to the laboratory (i.e., submit groundwater samples on one chain-of-custody batch separate from soil samples collected for the same project).

Figure 11-1

Figure 11-1. Example Chain-of-Custody Form.
[Source: US Navy, 2007]

Shipping companies (e.g. Federal Express, DHL, etc.) are not expected to sign the chain-of-custody form. However, complete shipping documentation, including tracking numbers, becomes part of the chain-of-custody record. When using shipping companies, the last person to have custody of the samples must fill in both the relinquished section (as normal) as well as the received section (identifying the shipping company's name and the date and time when the shipment was given into custody of the shipping company).

Once received at the laboratory, custody procedures shall apply. It is then the laboratory's responsibility to maintain custody records throughout sample preparation and analysis. An example generic chain-of-custody form is presented in Figure 11-1.

11.3.2.2 Chain-of-Custody Seals

To ensure sample integrity when shipping samples, use custody seals. The custody seals must be dated and initialed by the personnel responsible for custody of the samples. Intact custody seals when the samples are logged into the laboratory indicate the physical integrity of the sample was not compromised during sample shipment.

Use custody seals on the outside of each container or cooler when shipping samples. Two seals are required, one at the front or opening edge of the cooler and one at the rear or hinged edge of the cooler. Clear tape can be applied over the custody seals when sealing the cooler or container for shipment.

Shipping sample coolers from the outer islands to O`ahu or to mainland laboratories may require inspection by the Transportation Security Administration (TSA), which may break the chain-of-custody if custody seals are only used on the outside of shipping coolers. In this event, ensure individual sample integrity through the use of custody seals on individual sample container lids.

Custody seals may not be necessary if the sampling personnel retain custody of the samples from the time of collection to the time of delivery to the analytical lab, if the samples are delivered in person and a shipping company is not used.