Diseases Caused by Halogen Derivatives of Aliphatic or Aromatic Hydrocarbons

1. Introduction and Definitions

Halogen derivatives of aliphatic or aromatic hydrocarbons, also known as halogenated hydrocarbons, are compounds where one or more hydrogen atoms in the hydrocarbon are replaced by halogen atoms (fluorine, chlorine, bromine, or iodine). These compounds are widely used in various industrial applications, including solvents, refrigerants, pesticides, and pharmaceuticals. However, exposure to these chemicals can lead to significant health issues, affecting the liver, kidneys, central nervous system, and respiratory system. This article provides comprehensive information on diseases caused by halogen derivatives of aliphatic or aromatic hydrocarbons, targeting occupational health nurses and doctors.

2. Agent Causes the Disease

Halogenated hydrocarbons can cause disease through inhalation, ingestion, or dermal contact. Common agents include:

  • Chlorinated Hydrocarbons: Such as chloroform, carbon tetrachloride, and trichloroethylene, used as solvents and in chemical manufacturing.
  • Brominated Hydrocarbons: Such as ethylene dibromide and bromoform, used in pesticides and fire retardants.
  • Fluorinated Hydrocarbons: Such as chlorofluorocarbons (CFCs) and hydrofluorocarbons (HFCs), used as refrigerants and propellants.
  • Iodinated Hydrocarbons: Less commonly used but still present in certain industrial applications.

3. Workers at Risk of This Disease

Several occupations and tasks put workers at higher risk of exposure to halogenated hydrocarbons, including:

  • Chemical Manufacturing Workers: Handling halogenated hydrocarbons in the production of chemicals.
  • Laboratory Technicians: Using halogenated solvents and reagents in research and testing.
  • Pesticide Applicators: Handling and applying brominated pesticides.
  • Refrigeration and Air Conditioning Technicians: Working with refrigerants containing CFCs and HFCs.
  • Dry Cleaning Workers: Using chlorinated solvents in cleaning processes.
  • Firefighters: Exposure to brominated fire retardants during firefighting activities.

4. Symptoms

Symptoms of exposure to halogenated hydrocarbons can vary depending on the compound, level, and duration of exposure:

  • Acute Exposure: Symptoms include dizziness, headache, nausea, vomiting, fatigue, and irritation of the eyes, skin, and respiratory tract. Severe exposure can lead to central nervous system depression, liver and kidney damage, and respiratory failure.
  • Chronic Exposure: Long-term exposure can cause liver and kidney damage, central nervous system effects such as memory loss and cognitive impairment, and an increased risk of certain cancers.

5. Diagnosis

Diagnosing diseases caused by halogenated hydrocarbons involves a combination of clinical evaluation, occupational exposure assessment, and specific tests:

  • Medical History and Physical Examination: Detailed assessment of the patient's work history and symptoms.
  • Blood and Urine Tests: Measuring levels of halogenated hydrocarbons and their metabolites to assess exposure.
  • Liver and Kidney Function Tests: Monitoring organ function for signs of damage.
  • Neurological Evaluation: Including tests for cognitive and motor function.
  • Imaging Tests: X-rays, CT scans, or MRIs to detect organ damage and central nervous system effects.

6. Treatment

Treatment for diseases caused by halogenated hydrocarbons focuses on managing symptoms and preventing further exposure:

  • Remove from Exposure: Immediate removal from the source of exposure is crucial.
  • Symptomatic Treatment: Providing medications to manage respiratory, neurological, and gastrointestinal symptoms. This may include bronchodilators, pain relievers, and therapies for cognitive and mood disorders.
  • Supportive Care: Including oxygen therapy for respiratory issues, dialysis for kidney failure, and liver support treatments.
  • Long-term Monitoring: Regular follow-up to monitor liver and kidney function, as well as neurological health.

7. Prevention

Preventing diseases caused by halogenated hydrocarbons involves implementing strict control measures in the workplace:

  • Engineering Controls: Using local exhaust ventilation, enclosed processes, and proper maintenance of equipment to reduce airborne exposure.
  • Work Practices: Implementing safe work practices such as proper handling and disposal of halogenated hydrocarbons, and avoiding eating, drinking, or smoking in areas where these compounds are used.
  • Personal Protective Equipment (PPE): Providing and ensuring the use of appropriate respirators, protective clothing, and gloves.
  • Health Surveillance: Regular health screenings, including liver and kidney function tests, and neurological assessments for workers exposed to halogenated hydrocarbons.
  • Education and Training: Informing workers about the hazards of halogenated hydrocarbons and safe work practices to minimize exposure.

By recognizing the hazards of halogenated hydrocarbons and applying effective preventive strategies, occupational health professionals can substantially lower the occurrence of related illnesses and improve the overall health and safety of workers.

Workplace Exposure Limits:

Freon-11 (CCl2F2)

  1. OSHA PEL (Occupational Safety and Health Administration):

  2. NIOSH REL (National Institute for Occupational Safety and Health):

    8-hour TWA: 1000 ppm or 4950 mg/m³.

Freon-12 (CClF2CClF2)

  1. OSHA PEL (Occupational Safety and Health Administration):

  2. NIOSH REL (National Institute for Occupational Safety and Health):


  • NIOSH REL: 2 ppm (12.6 mg/m3) 60-minute STEL
  • NIOSH considers carbon tetrachloride to be a potential occupational carcinogen as defined by the OSHA carcinogen policy.


  1. OSHA PEL (Occupational Safety and Health Administration):
  2. 8-hour Time-Weighted Average (TWA): 20 parts per million (ppm) or 30 ppm not to be exceeded during any 15-minute work period. Additionally, a maximum peak exposure of 50 ppm is not to be exceeded during any 5-minute work period.

  3. NIOSH REL: 0.045 ppm TWA, 0.13 ppm 15-minute CEILING; NIOSH considers ethylene dibromide to be a potential occupational carcinogen as defined by the OSHA carcinogen policy [29 CFR 1990].