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OSAC’s purpose is to strengthen the nation's use of forensic science by providing 

technical leadership necessary to facilitate the development and promulgation 

of consensus-based documentary standards and guidelines for forensic science, 

promoting standards and guidelines that are fit-for-purpose and based on sound 

scientific principles, promoting the use of OSAC standards and guidelines by 

accreditation and certification bodies, and establishing and maintaining working 

relationships with other similar organizations.

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The six subcommittees of the Chemistry/Instrumental Analysis SAC include Fire 

Debris and Explosives, Geological Materials, Gunshot Residue, Materials (Trace), 

Seized Drugs and Toxicology. 

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This resource is intended to provide a brief overview, or the “what”, “why”, 

“where”, and “how”, of the field of Forensic Toxicology.

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Toxicology is the study of drugs and chemicals on biological systems. Toxicology

relies on information from numerous scientific and social disciplines as well as 

engineering and statistics. 

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Forensic toxicology deals with the application of toxicology to cases and issues 

where adverse effects of the use of impairing, toxic and lethal concentrations of 

drugs have administrative or medicolegal consequences, and where the results 

are likely to be used in a legal setting. 

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Other career opportunities exist in hospitals, universities, and industry.

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Paracelsus is often credited with one of the original conceivers of toxicology. 

Manly Hall, a famous author of the 19th Century called him "the precursor of 

chemical pharmacology and therapeutics and the most original medical thinker 

of the sixteenth century.“

A principle tenet of forensic toxicology is that the “dose makes something a 

poison”. For example, water is generally a safe and essential beverage all living 

organisms require to live, but if taken in an excessive amount this can interfere 

with a body’s chemistry and create a toxic environment. 
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Pharmacology is the study of the effects of drugs on humans. Drugs are 

chemicals designed to have a biochemical or physiological effect on biological 

systems, while poisons are substances with life-threatening effect

Drugs and poisons are often reduced by the body to a chemical form known as a 

metabolite that promote its excretion from the body. 
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Pharmacokinetics is the branch of pharmacology concerned with the movement 

of drugs within the body. It is paired to Pharmacodynamics, or the study of how 

drugs act in the body. Pharmacokinetics represents what the body does to the 

substance and Pharmacokinetics represents what the drug does to the body. 

Certain organs in the body, especially the brain, have receptors for which drugs 

can bind to exert its effects. These effects can be functions or processes. For 

example, a drug can cause secretion of a hormone such as insulin from the 

pancreas.
The field of forensic toxicology involves three main sub-disciplines: postmortem 

forensic toxicology, human performance toxicology, and forensic drug testing. 

All of these sub-disciplines measure substances in biological matrices for a 

given purpose.

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In postmortem forensic toxicology, forensic toxicologists work with 

pathologists, medical examiners, and coroners to help establish the role of 

alcohol, drugs, and poisons in the causation of a death. Postmortem Toxicology 

investigates suspected drug overdoses, homicide, suicide, natural deaths and 

general unknown deaths where toxins are either ruled in or out through testing

and interpretation.

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Biological fluids include blood, urine, vitreous fluid, cerebral spinal fluid, and 

bile. In addition to tissues, hair, nail and, in some cases, bone can be used in 

toxicological analysis. 

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Once the testing is complete, a forensic toxicologist then interprets these 

findings. This information helps a forensic pathologist determine the cause 

and manner of death.

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Criminal investigation analysis involves the same application of techniques as in 

the death investigation setting, but specimens are typically collected from living 

persons. Blood and urine are commonly encountered, but oral fluid, hair, and 

other specimens are also used. If samples are taken from a clinical 

environment, plasma and serum can be used instead of whole blood with a 

conversion calculation. Forensic toxicologists are frequently asked to determine 

the timing and extent of impairment resulting from different patterns of drug 

and alcohol use. The interpretation of the test results in this area is the greatest 

challenge, requiring the application of knowledge from clinical and medical 

studies and experience in the field, to give an opinion about the effects of a 

drug or combination of drugs on an individual at the time of a crime or 

accident.

Specimens with a shorter window of detection include blood, urine, breath, and 

oral fluid, whereas long-term detection can use alternative matrices like hair, 

nails,, or sweat.

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The scope of drug testing is often limited however, compared with human 

performance or postmortem toxicology, but the throughput of testing can be 

greater. Workplace drug testing laboratories may perform tens of thousands of 

tests per day and many times require specialized configurations of equipment 

such as multiplexing, which decreases analysis time and improves 

productivity. Urine is the most common specimen tested but oral fluid, hair, 

sweat, and other matrices are also used. As with all of the forensic disciplines, 

there is a strong emphasis on record keeping, chain-of custody documentation, 

stringent quality control, and data management.

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Briefly the steps in forensic analysis or treatment of the specimen to get an 

answer include:

Isolation of the drug/poison from the matrix, be it blood or vitreous. To do this 

some type of extraction method is employed to remove the substance from the 

biological matrix. Detection and characterization of the poison by comparison 

with known quality control reference materials (controls), calibrators, and drug 

libraries is the next step. Identification of the drug, or confirmatory testing, by 

matching retention times and spectrum of an unknown substance in a sample 

to a known substance in the drug library. Quantification when a concentration 

of the substance is determined by comparison to values of a calibration curve 

analyzed on the same run as the samples. Once data is reviewed, a forensic 

toxicologists considers all the results, the case information, and known 

literature to interpret the toxicological findings in a case.

Some of instrumentation is so precise that it is like getting a ‘toxicological 

fingerprint’ that is unique to one specific substance, referred to as an analyte. 
The field of Forensic Toxicology utilizes various testing techniques to 

determine the presence of drugs or chemicals in a biological system.

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Some enter toxicology after working in, or pursuing education in, other areas 

such as medicinal chemistry, pharmacology, or clinical chemistry. While 

relevant educational requirements are necessary to enter the field of forensic 

toxicology, training in the laboratory furthers an individual’s knowledge, 

experience, and ability to provide interpretation of the results. The American 

Board of Forensic Toxicology (www.ABFT.org) offers professional certification 

to scientists working in the field of forensic toxicology.

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Forensic sciences for the most part occurs in the laboratory where the 

natural sciences can be performed in a setting that is reliable and will not 

impact the results of the investigation. Research laboratories are also a 

location for forensic toxicology to be performed in an even greater 

controlled environment. Roadside testing and scene investigations are 

also two more locations where the beginning of forensic toxicology is 

performed, namely to collect specimens and to do some of the initial 

testing. Consultation and Expert Services that include Expert 

Testimonies for court proceedings, laboratory inspections, and other 

investigations that need the expert opinion of a forensic scientist.
There are many professional organizations who members practice forensic 

toxicology and whose annual meetings present cases and research in the field. 

The Society of Forensic Toxicology (www.soft.org) primarily represents 

toxicologists in the United States, while TIAFT and AAFS have a more 

internationally represented membership. Regional meetings for forensic 

toxicologists include the California Association of Toxicologists and the 

Southeastern Association of Toxicologists. The American Board of Forensic 

Toxicology offers board certification for this profession. 

These websites provide additional details concerning career opportunities and 

advances in the field of forensic toxicology.

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Forensics is a growing field and there is all kinds of literature out their to 

feed your hunger for knowledge of this field and to help you plan your 

career path. Here are a few organizations and Federal Agencies that 

provide additional information.