Orientation and Training
Food and Drug Administration
Many complaints allege product tampering; however, frequently facts uncovered during the investigation do not support the allegations. Prior to laboratory examination and analysis (unless there is prevailing investigational information), it is difficult to differentiate manufacturing problems from intentional tampering. Consequently, the analytical approach is usually the same for both.
There are three distinct scenarios in which a product may be adulterated:
- During manufacture as the result of error, accident or sabotage.
Examples of instances initially thought to be tampering (because only a few units were affected) but were eventually linked to manufacturing problems include the following: contamination of a product with cleaning solution due to incomplete rinsing of processing equipment, foreign objects such as metal fragments or machine parts present in the product due to equipment failure, and a incorrect product inside a container due to labeling mix-ups.
- During distribution as the result of a tampering, the product is often disguised or covered up so that the product appears "normal".
The most infamous example is the 1982 case in which seven people in the Chicago area died after taking Tylenol capsules poisoned with cyanide
- After the product is in the possession of the consumer.
Examples are the "copy cat" or false report cases that may follow a highly publicized tampering. Intentional poisoning of a person is another example of this tampering scenario. There can also be instances in which the consumer unknowingly contaminates the product himself/herself. One example is when the suspicious tablets or capsules found in a beverage are the same as the tablets or capsules the consumer was attempting to swallow some time prior to the "discovery".
The objective of the investigation and analysis of complaint/tampering samples is as follows: determine if the product is adulterated or substandard; determine the nature/identity and extent of the adulteration; and evaluate, if possible, which of the three adulteration scenarios listed above is most likely and/or which, if any, can be ruled out. This assessment represents an ideal situation. In reality, the ability to resolve these issues with absolute certainty is often limited by the details of the complaint, as well as the history and condition of the sample received by the laboratory.
Prior to starting the analysis:
Obtain as much background information as possible. Read the complaint form, collection report and affidavits and discuss the sample with the investigators. At this point it is important to differentiate facts from allegations and theories. Facts are when a product was manufactured (as determined from code/lot number/expiration date) and when the complaint was made. Allegations, e.g. statements the product tasted bitter or made the consumer nauseous, may or may not be accurate or true. Information obtained from the manufacturer on previously encountered packaging or product defects is beneficial. Medical records can provide important clues in cases involving death, serious illness, and injuries. For example, medical tests may indicate that the consumer ingested a reversible cholinesterase inhibitor in which case it would be sensible to screen the sample for carbamate pesticides. Some guidance in this area can be obtained from toxicology texts (4, 5) or through consultation with local Drug and Poison Information Centers or toxicology laboratories.
Whenever possible, obtain a control sample of the product for comparison to the suspect sample. For the most meaningful comparison, the control should closely match the suspect with respect to product, packaging, manufacturing location, and time. There should also be some assurance that the control is intact and free of contamination. In the absence of a well-matched control, one alternative is to use a sample with nominally the same suspect sample matrix as a comparison control for chemical tests.
General guidance on the examination of materials for forensic purposes can be found in an excellent collection of monographs (6, 7, 8).
The FDA Forensic Chemistry Center (FCC) located in Cincinnati, Ohio, has extensive experience in dealing with product tampering samples. Contact them whenever there are questions about the approach to the analysis, the methods to use, or whether the FCC has prior experience with the type of complaint/tampering situation under investigation.
Forensic Chemistry Center: