What Is a Neurotoxin?
The EPA's Guidelines for Neurotoxicity Risk Assessment define neurotoxicity as an adverse change in the structure or function of the central or peripheral nervous system following exposure to a chemical, physical or biological agent. The National Institute of Neurological Disorders and Stroke says neurotoxicity happens when exposure to toxic substances affects the normal activity of the nervous system.
Metals, pesticides and solvents are well-known examples. The EPA guidelines cite outbreaks of methylmercury poisoning in Japan and Iraq, and neurotoxicity in miners of mercury, manganese and lead, among prominent historical episodes, and say organochlorines, organophosphates, carbamates, pyrethroids, certain fungicides and some fumigants are all known neurotoxicants. ATSDR says all forms of mercury can affect the nervous system, and that workers exposed to mercury vapor and people eating foods high in methylmercury experienced tremors, incoordination, impaired vision, impaired learning and memory, and mood changes.
The EPA guidelines say changes in peripheral nerve function are frequently associated with signs such as numbness, tingling or burning, and that solvents such as n-hexane produce peripheral neuropathy, where some compensation is likely because peripheral nerves can repair. To test chemicals, they describe functional observational batteries, many of which are essentially clinical neurological examinations, often in animals, that rate neuromuscular, sensory and autonomic signs such as weakness, incoordination, tremor, vision and pupil response.
Sources checked September 15, 2026. Every point below links the page it came from.
The sources behind this answer
- Medical referenceThe EPA's neurotoxicity guidelines define neurotoxicity as an adverse change in the structure or function of the central or peripheral nervous system after exposure to an agent. US EPA, Guidelines for Neurotoxicity Risk Assessment ↗
- Medical referenceThe National Institute of Neurological Disorders and Stroke says neurotoxicity happens when exposure to toxic substances affects the normal activity of the nervous system. National Institute of Neurological Disorders and Stroke ↗
- Government sourceThe EPA guidelines cite methylmercury poisoning outbreaks in Japan and Iraq and neurotoxicity in mercury, manganese and lead miners as prominent historical episodes. US EPA, Guidelines for Neurotoxicity Risk Assessment ↗
- Government sourceThe EPA guidelines say organochlorines, organophosphates, carbamates, pyrethroids, certain fungicides and some fumigants are all known neurotoxicants. US EPA, Guidelines for Neurotoxicity Risk Assessment ↗
- Government sourceThe EPA guidelines say solvents such as n-hexane produce peripheral neuropathy, where some compensation is likely because peripheral nerves can repair. US EPA, Guidelines for Neurotoxicity Risk Assessment ↗
- Government sourceATSDR says all forms of mercury can affect the nervous system, causing tremors, incoordination, impaired vision and memory, and mood changes in exposed people. ATSDR, CDC ↗
- Government sourceThe EPA guidelines say changes in peripheral nerve function are frequently associated with clinical signs such as numbness, tingling or burning. US EPA, Guidelines for Neurotoxicity Risk Assessment ↗
- Government sourceThe EPA guidelines describe functional observational battery tests as essentially clinical neurological examinations rating neuromuscular, sensory and autonomic signs. US EPA, Guidelines for Neurotoxicity Risk Assessment ↗
Sources checked September 15, 2026. A brand statement is the company’s own claim, which we report but have not verified. Our grades are model-based estimates, not lab tests.