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Forensic toxicology is a field within forensic science that focuses on detecting and assaying toxins and drugs in bodily fluids and tissues. It involves collecting samples, employing technical logical ways, and furnishing expert evidence in legal proceedings. Its operations range from felonious examinations to plant medicine testing and post-mortem examinations, contributing crucially to the legal system's pursuit of justice.


Forensic toxicology is a branch of forensic science concentrated on assaying bodily fluids and tissues to determine and quantify poisonous substances, drugs, and toxins. It plays a crucial part in legal examinations by providing substantiation of substance exposure, determining the cause of death, assessing impairment, and relating substances involved in wrongful activities or accidents.

Toxicology is the study of the adverse effects of chemicals on living organisms. Forensic toxicology takes it a step further, including a number of related disciplines to assist in the detection and interpretation of drugs and poisons in medicolegal death investigations, human performance issues; e.g., driving under the influence, compliance and other related matters. In these investigations, the three main objectives (respectively) are to: 


Forensic toxicology is a multidisciplinary field that combines principles from toxicology, pharmacology, and logical chemistry to aid legal examinations, particularly those involving poisoning, drug use, and death. It involves the discovery and interpretation of toxins in natural samples and encompasses several technical sub-disciplines such as:

  1. Postmortem Toxicology- This focuses on assaying bodily fluids and tissues from departed individuals to determine the presence of drugs, alcohol, or other poisonous substances. It's crucial in establishing the cause and manner of death, particularly in cases of suspected overdose, poisoning, or drug- related losses.
  2. Human Performance Toxicology- This area examines the goods of alcohol, drugs, and other substances on mortal behavior and performance. It's frequently applied in cases involving disabled driving, plant drug testing, sports doping, and assessing the impact of substances on a person’s capability to perform specific tasks.
  3. Forensic Drug Testing- This involves the discovery of lawless and prescription drugs in natural samples similar as urine, blood, hair, and slaver. It's extensively used in legal and workplace settings to ensure compliance with laws and regulations regarding drug use.
  4. Environmental Toxicology- This field studies the impact of chemicals, adulterants, and poisons set up in the terrain on mortal health and ecosystems. Forensic.environmental toxicologists might investigate cases of environmental impurity or poisoning, similar as artificial chemical tumbles or pesticide exposure.
  5. Clinical Toxicology- It focuses more on the diagnosis and treatment of poisoning in living cases. Forensic clinical toxicologists may be involved in legal cases where an individual’s health was negatively affected by exposure to poisonous substances.
  6. Doping Control- This involves the discovery of performance- enhancing drugs and banned substances in athletes. Forensic toxicologists in this area ensure compliance with anti-doping regulations in sports and play a pivotal part in maintaining fair competition.
  7. Forensic Toxicokinetics and Toxicodynamics- This area studies the immersion, distribution, metabolism, and excretion (ADME) of drugs and poisons, as well as their biochemical and physiological goods. Understanding these processes helps forensic toxicologists interpret drug situations in the body and their implicit goods at the time of an incident.
  8. Occupational Toxicology- This sub-discipline deals with the health goods of chemicals and other dangerous substances encountered in the plant. Forensic occupational toxicologists may be called upon to probe plant exposures and assess whether they contributed to illness or injury.


In post-mortem investigations, suspected drug overdoses are clear situations where toxicology is required to establish if an excessive intake of the drug occurred and, if so, whether this contributed to death. Conversely, toxicology can eliminate the possibility of a drug overdose if concentrations are not capable of causing death, given all other factors.

This means that toxicology testing can produce a positive result even in cases where drug use is not mentioned in the police circumstances. This is not surprising as given the wide availability of potentially toxic substances, both legal and illegal. In addition, concentrations of substances change after death making any interpretation difficult, no matter the concentration. 

In many cases, poisons may be detected by the toxicology laboratory but are not necessarily a cause of death, rather their presence may be relevant in the circumstances of death. For example, alcohol and impairing drugs are found in about half of all drivers killed in motor vehicle crashes in Australia, nearly one-third (31%) of all traffic-related deaths in the United States and in a significant proportion of other accidental deaths. Alcohol and/or drugs are also found in a significant number of other deaths reported to the coroner.

For example, in suicides that include non-drug related intentional deaths. In death cases where natural disease is partially to blame, drugs that indicate an underlying disease are often detected, such as drugs that have been used to treat a condition or pain. 

Sometimes these drugs are regarded as contributing to the cause of death. Regardless how the individual died, toxicology testing can determine whether levels of toxic substances may have contributed to this death.


Death Investigation toxicology, also known as posthumous toxicology, involves the analysis of natural samples from departed individualities to identify and quantify drugs, toxins, and other chemicals. This field is pivotal for determining the cause and manner of death, particularly in cases of suspected drug overdose, poisoning, or other toxicological factors. 

  • Specimens Collection:

(Table 1) below, provides a detail of the kinds of samples commonly requested when investigating different manners of death, although there may be unique case needs that have to be addressed for some investigations.

Type of death case Recommended specimens
1.    Suicides, motor vehicle crashes, and industrial accidents
1.    Heavy metal poisoning and exposure to other poisons
2.    Homicides and/or suspicious 2.    Blood, urine, vitreous humor, gastric contents, bile, liver, hair
3.    Drug-related 3.    Blood, urine, vitreous humor, gastric contents, bile, liver, hair
4.    Volatile substance abuse 4.    Blood, urine, vitreous humor, lung fluid or tied-off lung, liver
5.    Heavy metal poisoning and exposure to other poisons 5.    Blood, urine, vitreous humor, liver, hair, kidney
  • Blood, Urine, Liver 

Blood is often the specimen of choice for detecting, quantifying and interpreting drugs and other toxicant concentrations. Concentrations of drugs and other toxicants in blood may be useful for establishing recent drug ingestion and to determine the effect of a drug on the deceased at the time of death, or at the time the blood was taken. This can complicate the investigation when someone has been taking prescription medications for some time. 

For cases involving hospital treatment before death, blood samples taken soon after admission and immediately before death, should also be investigated particularly when poisoning is suspected before admission into hospital. Any treatment given can change the results of toxicology tests or be helpful in the investigation.

Post-mortem blood presents problems due to often variable condition and changes to concentrations from one place to another in the body after death. The degree of decomposition can also interfere with testing as these specimens can be difficult to analyze. 

  • Urine is the most common sample used for drug testing in the workplace, but it is not always available for post-mortem testing. Urine testing results do not directly correlate to drug effects at the time of sample collection because of the time it takes the body to eliminate these drugs or their metabolites (the body’s breakdown products) in the urine. Its usefulness lies in the fact that the presence of a substance in the urine is a sign that the substance had been in the blood at an earlier time (usually within a few days) and had been somewhat processed, detecting these metabolites gives proof that the drug had been ingested. The liver is a primary solid tissue for use in post-mortem toxicology because it is where the body metabolizes most drugs and toxicants. Many drugs become concentrated in the liver and can be found even when there are no levels in the blood. In this latter situation, interpretation of findings is complex.
  • Vitreous Humor: It is the clear, gel-like substance that fills the eye. It can be a useful fluid to screen for a range of drugs. Vitreous humor is commonly analyzed for blood alcohol concentrations. This is of particular interest in motor vehicle trauma, workplace accidents, suicides and homicides. Vitreous humor alcohol concentrations are a little higher than blood (about 20% on average), assuming there has been no degradation. Interpretation of other toxicological findings in vitreous humor is somewhat more complex
  • Stomach Contents - Because drugs and poisons can often be ingested, stomach contents can provide important investigative clues. In a case of potential overdose or acute poisoning, high concentrations of drugs or toxins may be detected, depending on how much time elapsed between ingestion and death. In many cases of acute poisoning, undissolved capsules or tablets may be discovered, allowing relatively simple drug or poison identification. The total amount of a drug or poison present in the stomach is more important than its concentration because it has not been processed by the body yet. 
  • Bone and Bone Marrow - Bone, in particular bone marrow, can be used for testing when necessary, but the availability and condition of bones in skeletal remains may limit their usefulness. There are no data to suggest that bones from one part of the body are better than others for toxicology tests.However, it is always easier to extract samples from larger bones. Interpretation of these findings is often difficult when assisting in a death investigation, because the time that these toxins were deposited in the bones cannot be determined with reasonable certainty. 
  • Hair and Nails - Hair specimens, usually taken from the back of the head, can be used to test for exposure to heavy metals and drugs over a period of weeks to months. Hair is predominantly used to test for drugs such as amphetamines, cocaine, marijuana (THC) and heroin, and more recently tests have been created to determine if the deceased was drinking heavily in the last few months before death. Drug analysis can also be done on finger and toenails in order to provide an even longer potential window of exposure than hair. However, relatively little is known about how the nails process toxins, so interpretation of results is more difficult. Hair is subject to external contamination issues that can mitigate its value, so special sample preparations in the lab may be needed for a given case.The testing of biological fluids and/or tissues for drugs and other substances is a complex process requiring sophisticated instrumentation and specially trained analysts. In the typical autopsy, fluids and tissue samples are collected specifically for toxicology testing. The types of samples collected from the body, and the testing targets in these biological fluids and tissues, are determined by circumstances of the case and the condition of the body.Once at the laboratory, a series of tests will be conducted, usually on blood, for a large range of over-the-counter, prescription and illicit drugs as well as alcohol and other toxicants; e.g., metals, inhalants, pesticides, insecticides, carbon monoxide, cyanide and many other possible toxins depending on investigative clues or specific tests requested. “Systematic Toxicological Analysis” section (both provided below) spell out the many materials the medical examiner might harvest from a body during autopsy, and how they can be quickly screened in “truly unknown” cases. The biological evidence from autopsies are needed to support both “common” lab tests and help investigate some very specific potential causes of death.Routine testing, or testing without specific instructions to look for a particular substance, will generally include the drugs shown below in Table 1, but not all drugs. The list of the most common drugs detected is included in a standard attachment to all toxicology reports. When urine is available, tests are also conducted for presence of drugs of abuse. Depending on the case and the results of initial testing other tissues may need to be analyzed, possibly including stomach contents, liver, etc.


Death by poison can happen in a variety of ways, for example through recreational exposure by inhaling solvents such as butane lighter fluid or fuels, ingesting plant-derived substances like Angel’s Trumpet, accidental exposure to a substance used in the workplace or even accidently produced in the home (like carbon monoxide), or suicidal ingestion of a poison such as strychnine, pesticides, cyanide, etc. These all require specialized tests and the laboratory is alerted to their possible usage or involvement in the death when requests for toxicology testing are submitted.


Forensic toxicology plays a pivotal part in detecting toxins and drugs, both in answer control and in broader forensic examinations. Methods where doping control intersects with forensic toxicology, fastening on the ways, substances tested, and the challenges faced

Objectives: Human performance toxicology focuses on evaluating how substances affect an individual’s ability to perform tasks and make decisions. It aims to understand functional impairment by assessing how substances influence cognitive and physical abilities, such as reaction time, coordination, and judgment. In contrast, other forms of forensic toxicology are primarily concerned with identifying and quantifying drugs and toxic substances in biological samples to determine their presence, concentration, and potential contribution to a person’s death, injury, or drug use.

 Applications: While traditional forensic toxicology is often applied to criminal investigations, post-mortem examinations, and cases involving poisoning or drug-related deaths, human performance toxicology is applied in contexts where understanding impairment is essential, such as workplace safety, traffic accidents, and sports doping cases.


  1. State of Maharashtra v. Shri Prakash -This case dealt with the admissibility of toxicological substantiation in court. The Bombay High Court held that forensic toxicology reports are permissible as substantiation, handed they fulfill the criteria of applicability and trustability.
  2. State of Maharashtra v. Kaluram - In this case, the Bombay High Court emphasized the significance of duly conducting forensic toxicology tests and icing the chain of guardianship to maintain the integrity of substantiation.
  3. State of Maharashtra v. Ramdas- This case, although there are several cases by the same name, involved the use of forensic toxicology to establish the cause of death in poisoning cases. similar cases frequently calculate heavily on forensic toxicology reports to determine whether poisoning was the cause of death and to identify the specific bane used.
  4. State of Karnataka v M. Krishna- This case involved the use of forensic toxicology to discover drugs in the system of individualities indicted of drug- related offenses. The court depended on the forensic toxicology report to establish the presence of drugs and to condemn the indicted.


Forensic toxicology plays a pivotal part in the justice system by detecting and relating toxins and drugs in natural samples. This field combines principles from chemistry, biology, and drug to give vital information in unlawful inquiries, legal cases, and medical emergencies. By understanding the mechanisms of various poisons and the strategies used to ascertain them, forensic toxicologists can help uncover the trueness in suspicious deaths, drug overdoses, and cases of poisoning.

The field is continually evolving with advancements in technology and logical ways, allowing for more precise and rapid discovery of substances. This progress enhances the capability of forensic toxicologists to give accurate and dependable results, which are essential for legal and medical decision- making.

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