CHAIN OF CUSTODY AND INDOOR ENVIRONMENTAL QUALITY

By: Dr. Rajiv Sahay, Laboratory Manager 

Environmental Diagnostic Laboratory

The success of any Indoor Environmental Quality (IEQ) investigation is dependent on great extent to the quality and completeness of the Chain of Custody form. The Chain of Custody is a written document that refers the ability to guarantee the identity and integrity of a specimen collected from various sites for analysis.  To provide valid, credible and legally sound laboratory test reports, it is essential to have a proper Chain of Custody form. The Chain of Custody is vital not only for the authenticity of the collected samples, but also for the correct and accurate analysis of the submitted specimen.

The importance of chain of custody can be easily understood as an acronym: A.L.A.R.M.

1. Authenticity:

A Chain of Custody is fundamental to attest to the truth, genuineness, accuracy, and validity of a collected sample. The authenticity of any collected environmental sample can be maintained only after completing an appropriate Chain of Custody form. Documentation is initiated simultaneously with the collection of the samples. The attending technician has to note the date, time, location and method used for collection.  The technician farther authenticates the above information by signing the Chain of Custody.

2. Legality: 

The Chain of Custody provides the legal evidence required to prove that sampling protocol was based on specific scientific methodology. Since the indoor environment is neither a constant object nor a constant condition, the chain of custody tells us about the actual circumstances surrounding the specimen at the time, date and location of collection. Once a specimen has been thoroughly analyzed by the laboratory, standard operating procedure dictates that the sample be discarded according to laboratory protocol.  Therefore, only the Chain of Custody serves as a written record of relevant information pertaining to the analyzed specimen.  The Chain of Custody has particular importance in the event of legal disputes.

3. Accuracy:

The accuracy of laboratory findings is directly related to the accuracy of the sample collection.  Thusly, the Chain of Custody is needed to ensure that the specimen was collected utilizing proper tools and procedures.  Transportation, storage and handling of the environmental sample sometimes influences laboratory results, especially in the case of fast growing microorganisms, which include bacteria and fungi.  These entire confounding variables make the Chain of Custody a highly beneficial tool to the field technician as it helps in maintaining the accuracy of the specimen’s collection.  The laboratory also uses a Chain of Custody form to document laboratory procedures.  The laboratory bears the burden of proving that the specimen was received, handled and processed by authorized laboratory personnel.  The condition of the specimen is an important consideration before proceeding with the actual analysis.  For this reason, the laboratory makes note of any unusual characteristics of the specimen.

4.  Reliability:

The reliability of the investigation and laboratory analysis is directly related to the methodology used to collect the sample. A good Chain of Custody form will ensure that a technician who followed the specified sampling methodology collected the specimen. It is the Chain of Custody that provides the specification for instruments to be used for sample collection and how it is to be collected.  Understanding how the sample was collected, where it was collected from, and the conditions surrounding also helps in reliable interpretation of the data.

5. Maintenance:

Needless to say, meticulous record maintenance is a vital part of any investigation. The Chain of Custody plays a pivotal role in maintaining the chronological history of sample collection. Sometimes keeping the specimen physically for a longer time is not possible, under such condition it is the Chain of Custody that authenticates information regarding the specimens. The detailed information includes the name of the person collected the specimen and each person or institutional entity that subsequently has custody of it at different stages of the investigation.  Good Chain of Custody forms will provide areas to include brief descriptions about the specimen along with other relevant information such as confounding variables.

As we have seen, the Chain of Custody form plays a role in IEQ investigations that is as important as the technician or the laboratory.  Without a solid Chain of Custody form, neither the technician nor the laboratory has any defensible or dependable documentation. A thoroughly completed Chain of Custody along with expert laboratory analysis and systematic investigations lend to reliable, credible and informative data. It serves to protect the client and the laboratory in the likely event of legal disputes. Most importantly, a good Chain of Custody form helps the IEQ professional better serve his/her clients by allowing accurate interpretation of results and maintainance of professional integrity.