A fecal occult blood (FOB) card is a diagnostic tool used to screen for the presence of hidden, or “occult,” blood in a stool sample. This test is primarily utilized as a non-invasive screening method for various conditions affecting the gastrointestinal tract, such as colorectal cancer, polyps, or internal bleeding from ulcers or diverticulitis. The process involves applying a small sample of feces onto a specialized card, which is then sent to a laboratory for chemical analysis. Because these cards contain human biological material, their transport must be classified and packaged according to strict regulations to ensure safety and legal compliance during transit.
Understanding Specimen Classification Categories
The transport of diagnostic specimens is governed by international and domestic regulations, which categorize materials based on their potential risk to public health. These rules, established by bodies like the International Air Transport Association (IATA) and the U.S. Department of Transportation (DOT), define three primary classifications for biological samples.
The highest risk category is Category A, designated for infectious substances transported in a form capable of causing permanent disability, life-threatening, or fatal disease in otherwise healthy individuals upon exposure. These extremely high-risk materials are assigned the United Nations numbers UN 2814 or UN 2900.
The next classification is Category B, which applies to infectious substances that do not meet the high-risk criteria for Category A. This group includes substances that are infectious but are not generally capable of causing severe disability or fatal disease, and they are assigned the identification number UN 3373. The third, lowest-risk classification is the Exempt Human or Animal Specimen, which applies to patient materials for which there is a minimal likelihood that pathogens are present.
Specific Classification of Fecal Occult Blood Cards
Fecal occult blood cards, when used for routine, non-suspect screening, are most commonly classified as an “Exempt Human Specimen” for shipping purposes. This designation is appropriate because the test is designed to detect blood, not to screen for or confirm the presence of high-risk pathogens. The general criteria for exemption require a minimal likelihood of infectious agents being present, which applies to routine colorectal cancer screening.
This classification is based on the professional judgment that the sample is not being collected from a patient known or reasonably suspected to have a severe, transmissible infectious disease. If the sample is known or suspected to contain a high-risk pathogen, such as a Category A agent, the shipment must be reclassified as Category A or Category B. Note that some specific domestic carriers, like the United States Postal Service, may have distinct rules requiring Category B packaging even for routine screening.
Required Procedures for Compliant Shipping
Even when classified as an Exempt Human Specimen, the FOB card shipment must still adhere to stringent safety standards to protect all personnel involved in the transport chain. The fundamental requirement is the use of a triple packaging system, which consists of three layers designed to contain the specimen in the event of a leak or damage.
The first layer is the primary receptacle, which is the foil pouch or container holding the card itself and must be leak-proof. The primary receptacle is then placed inside a leak-proof secondary packaging, which provides an additional barrier of protection.
Finally, the secondary packaging is secured within a robust outer packaging that is strong enough to withstand the shocks and vibrations typically encountered during transit. This outer box must have at least one surface dimension that is a minimum of 100 mm by 100 mm.
The outer packaging must be clearly marked with the words “Exempt Human Specimen” to communicate the classification to transport personnel. Unlike Category A or B shipments, a Shipper’s Declaration for Dangerous Goods is not required for exempt materials. However, the package must include the name and telephone number of a responsible person who can provide information about the contents in case of an emergency.