Abstract

Organic solvents are used in detergents, insecticides, and a number of industrial settings. Most of these substances are highly lipid-soluble and therefore capable of causing CNS disorders and polyneuropathy. Some organic solvents break down into metabolites that are carcinogenic. While the metabolites may be found in urine or blood, the diagnosis is usually established based on clinical features and a history of exposure. Most organic solvents do not have an antidote; therefore, treatment is generally supportive.

For an overview of other types of substance toxicity (e.g., with organophosphates), see the learning card on poisoning.

Overview

Overview of some organic solvents

	Effects
Aromatic amines	Transitional cell carcinoma of the bladder
Lindane	CNS: dizziness, vertigo, headache
Polyvinyl chloride	Hemangiosarcoma CNS: ataxia, coma Scleroderma-like skin changes
Hydrocarbons	Systemic toxicity (sensorimotor polyneuropathy, cardiac arrhythmias) If aspirated → aspiration pneumonia Benzene derivatives → methemoglobinemia

High lipid solubility

All organic solvents are highly lipid-soluble (i.e., lipophilic), which can lead to:
- Degreasing of the skin → eczema
- Mucosal irritation
- Permeation of the CNS, with symptoms based on the area affected (e.g, headache, chronic toxic encephalopathy)
- Peripheral neuropathy (e.g., polyneuropathy )

Chronic toxic encephalopathy

Etiology: chronic or repeated high-dose exposure (e.g,, inhalation) to organic solvents or heavy metals → cerebral, cerebellar, and brain stem atrophy
Presentation
- Mental conditions (e.g., personality changes)
- Multifocal neurologic deficits (e.g., memory impairment)
Grading

		Clinical features	Diagnosis	Prognosis
Stage I		Difficulty concentrating Poor memory Mood changes	History Psychopathological findings	Complete recovery within 2 years if no further exposure occurs.
Stage II	A	Symptoms: same as above Personality changes	Same as above Psychological evaluation to detect psychomotor retardation	Reduced healing tendency
Stage II	B	Symptoms: same as above Psychomotor deficits (e.g., ataxia)	Same as above Neurological evaluation to detect sensorimotor disturbances	Reduced healing tendency
Stage III		Dementia associated with pronounced memory problems and mental retardation	Detection of cerebral atrophy on cranial imaging	Improvement of symptoms rarely occurs

References:^[1]^[1]^[1]^[1]^[2]

Aromatic amines

Examples: benzidine, 2-naphthylamine, aniline
Sources of exposure: occupational sources (dyes, oil refining, rubber production, perfumes, pesticides), pharmaceuticals (e.g., benzocaine), and tobacco smoke
Effects
- Carcinogenic → transitional cell carcinoma of the bladder
- Benzene derivatives (e.g., aniline and benzocaine) → methemoglobinemia

References:^[1]^[3]

Quinone (benzoquinone)

Sources of exposure: inhalation, skin contact, or ingestion of oxidizing agents, bactericides, analytical reagents, or paint
Effects
- Eye Pain
- Blurry vision
- Brownish discoloration of the conjunctiva and the cornea
- Nausea, vomiting, abdominal pain
- Irritation of skin, mucous membranes, and respiratory tract
Diagnosis: clinical
Treatment: supportive

Dimethylformamide (DMF)

Sources of exposure: inhalation of or skin contact with solvent used to produce fibers, films, and coatings
Effects
- Nausea and vomiting
- Toxic hepatopathy (i.e., jaundice, alcohol intolerance, abdominal pain)
- Rashes
Diagnosis: clinical
Treatment: supportive

Formaldehyde

Sources of exposure: inhalation, skin/eye contact, and ingestion of disinfectants, tobacco smoke, or embalming fluid (an aqueous solution stabilized with methanol; formalin)
Effects
- Irritation of the skin (contact dermatitis), mucous membranes, eyes, and respiratory tract
- Headache, vertigo, sleeping disturbances, impaired cognition (memory, concentration)
- Metabolic acidosis
- Chronic exposure in high doses has a carcinogenic effects (especially in the nasopharynx).
Diagnosis: clinical
Treatment: supportive

Methyl n-butyl ketone

Synonyms: 2-Hexanone; propyl acetone
Sources of exposure: ingestion, skin contact, or inhalation of methyl n-butyl ketone, which is found in detergents, solvents, and paint thinners
Effects
- Headache, nausea, dizziness
- Irritation of the eyes, nose, and throat
- Axonopathy: bilateral and symmetrical sensory disorder and paralysis
Diagnosis: blood or urine detection of methyl n-butyl ketone
Treatment: supportive

Lindane

Sources of exposure: skin contact, ingestion, or inhalation of hexachlorocyclohexane found in insecticides or topical creams for scabies
Effects
- CNS: dizziness, vertigo, headache
- Carcinogenic effects are currently being investigated.
Diagnosis: HCH isomer detection in blood, urine, or semen

References:[6904;681]

Polyvinyl chloride

Sources of exposure: inhalation of or skin/eye contact with polyvinyl chloride, which is found in automotive parts, furniture, packaging materials, pipes, and wire coating
Effects
- Neurological changes (e.g., fatigue, dizziness, ataxia, visual disturbances, coma)
- Eye, mucous membrane, and respiratory tract irritation
- Chronic exposure: vinyl chloride disease
  - Abdominal pain
    - Liver, esophagus, and stomach injury
    - Splenomegaly
  - Malignant liver tumors (especially hemangiosarcoma)
  - Scleroderma-like skin changes

Diagnosis: detection of thiodiglycolic acid in urine

References:^[1]

Hydrocarbons

Classification and sources of exposure
- Aromatic hydrocarbon : benzene
  - Found in solvents, glues, nail polishes, cigarette smoke, car emissions, paints
  - Benzene derivatives:a hydrocarbon (e.g., xylene, toluene), amine group (e.g., aniline), or a nitro-compound (e.g.,nitrobenzene) attached to a benzene ring
- Aliphatic hydrocarbon ;: n-hexane, heptane, methane, ethane, propane, butane, octane
  - Found in gasoline or kerosene (solvents, paraffin wax, lighter fluid, furniture polishes, and lamp oil)
- Halogenated hydrocarbon ;: methylene chloride, chloroform, carbon tetrachloride, ; trichloroethylene , tetrachloroethylene
  - From biomass burning or natural production by fungi/bacteria
  - CCl4: formerly widely used in fire extinguishers, refrigerants, dry-cleaning fluids, and propellants
Effects
- Systemic toxicity
  - Neurotoxicity (e.g., sedation, headache, blurry vision, sensorimotor polyneuropathy; , chronic toxic encephalopathy, coma)
  - Cardiotoxicity (e.g., arrhythmias)
  - Nephrotoxicity (e.g., nephritis, nephrosis, and renal failure)
  - Carbon tetrachloride toxicity: free radical formation → centrilobular fatty change, congestion, and necrosis of the liver
  - Chronic benzene exposure: acute or chronic myeloid leukemia, non-Hodgkin lymphoma
- If aspirated → aspiration pneumonia
Diagnosis: clinical
Treatment
- Supportive (i.e., monitoring, fluid therapy, supplemental oxygen, intubation if in respiratory failure)
- Nasogastric lavage may be considered for patients who ingested a large amount of hydrocarbons with significant toxic potential and present within 1 hour of ingestion.

References:^[2]^[4]

Pyrethroid

Sources of exposure: skin contact with, ingestion of, or inhalation of insecticides (e.g., malaria control); permethrin treatment of scabies, head and pubic lice
Effects
- Headaches, dizziness, fatigue, coma
- Nausea
- Irritation of the skin and mucous membranes
Diagnosis: detection of pyrethroid metabolites in serum and urine
Treatment: supportive

Para-tertiary butylphenol formaldehyde resin

Sources of exposure: skin/eye contact with, ingestion of, or inhalation of adhesives, varnish, mineral oil, plastics, motor oil, fiberglass, or rubber processing fumes
Effects
- Contact dermatitis, skin burns
- Respiratory irritation
- Liver damage
- Goiter
Diagnosis: clinical or patch testing
Treatment: supportive

Carbon disulfide

Sources of exposure: skin/eye contact with or ingestion of coal tar, crude petroleum, or biodegradation mass inhalation
Effects
- Neurotoxicity (e.g., secondary parkinsonism, dizziness, headaches, polyneuropathy)
- Dermatitis
- Coronary heart disease
- Liver injury
Diagnosis: 2-thiazolidine-4-carboxylic acid in the urine
Treatment: supportive

Styrene

Sources of exposure: skin contact with, ingestion of, or inhalation of styrene released from disposed packaging materials, cigarette smoke, automobile emissions, or manufacturing of automobile parts, fiberglass, plastic pipes, and insulation for wiring and appliances
Effects (mainly due to inhalation)
- Fatigue
- Impaired vision
- CNS damage
- Polyneuropathy
- Irritation of the conjunctiva and mucous membranes
Diagnosis
- Urine analysis
  - Mandelic acid
  - Phenylglyoxylic acid
- Styrene in blood
Treatment: supportive