Nitrites are chemicals widely used as preservatives for meat and as anti-microbial agents in other food. They are commonly available as sodium, potassium, or ammonium salts. Nitrites are also abundant in the environment and are naturally occurring in some fruits and vegetables. Nitrates (-NO −3 ) on the surface of food can become nitrites (-NO −2 ) by the action of the bacterial enzyme nitrate reductase. Nitrates and nitrites are water soluble, and the presence of both forms can be minimized by washing food. Peeling the skin from vegetables and blanching them also minimizes nitrate/nitrite ingestion risk. Sodium nitrite as a pharmaceutical can be used to treat cyanide poisoning (Hope Pharmaceutical Sodium Nitrite Injection).Volatile products containing nitrites such as amyl nitrite have been used recreationally as inhalants for a euphoric effect during a state of mild hypoxia. Common exposure to small amounts is harmless.However, nitrites are able to oxidize the iron in hemoglobin from Fe +2 to Fe +3 yielding MetHb, and thereby reducing the oxygen-carrying capability of the blood. As such, when purposefully ingested in large amounts, nitrites can be fatal.

Analysis of subdural hematomata has been used to suggest antemortem drug concentrations, with the assumption that materials within the hematoma are less subject to metabolism or degradation during any survival period and postmortem interval. We report the case of an 87‐year‐old woman whose death had not been reported to the coroner's office until postembalming. Autopsy revealed a traumatic brain injury with subdural hematoma causing a mass effect. Testing of the clot indicated a methanol concentration of 51.8 mg%. No additional analyses were detected. These findings suggest that methanol can be present in a postmortem hematoma sample, yet not represent a poisoning. Our findings also suggest that while the interior of hematomata do not necessarily represent completely “protected space” from postmortem diffusion of some blood constituents, such diffusion is not facile, and analysis may still provide useful indications of antemortem drugs present, if not actual concentrations.