Methyl Isocyanate C2H3NO

1. Methyl Isocyanate (C2H3NO)

2. Methyl Isocyanate - Overview Physical properties Colorless liquid with a very distinct, sharp odor Highly flammable with low flash point Extremely toxic to people

3. Methyl Isocyanate - Overview A chemical intermediate in production of carbamate insecticides/herbicides 1984 accidental release in Bhopal, India killed 3-5,000 and injured 170,000

4. Methyl Isocyanate - Toxicity Extremely toxic to humans Inhalation exposure: LD50 < 200 mg/m3 Oral exposure: LD50 of 50-500 mg/kg 23 mg/m3 is irritating to the eyes, nose, and throat 68 mg/m3 results in a risk of severe injuries 225 mg/m3 may result in death

5. Methyl Isocyanate - Toxicity OSHA / NIOSH standards for skin exposure: TWA limit = 0.02 ppm (0.05 mg/m3) & IDLH = 3 ppm

6. Protective Equipment Diffuses through polyethylene and attacks most elastomers Wear protective clothing appropriate to the type and degree of contamination Positive-pressure, self-contained breathing apparatus (SCBA) is recommended

7. Detection No automated detection devices found

8. Decontamination Remove victims from the area of exposure, provide 100% O2 if inhalation has occurred Remove and double-bag contaminated clothing and personal belongings

9. Decontamination Eyes Flush with lukewarm water, 15 minutes Remove contact lenses Skin Flush skin and hair with water, 5 minutes Wash with soap and water, 15 minutes Rinse thoroughly

10. Signs and Symptoms Early effects of acute inhalation gaseous exposure Eye exposure: various adverse effects Continued exposure Difficulty breathing and cough develops Acute pulmonary edema and even acute respiratory distress syndrome

11. Signs and Symptoms Skin irritant causing a burning sensation Absorbed through the skin

12. Signs and Symptoms Highly toxic with oral exposure Reaches most organs in active form Systemic effects seen in animal studies Other systemic symptoms: nausea, gastritis, sweating, fever, and chills

13. Signs and Symptoms Bhopal accident Burning eyes most frequent symptom Cough associated with poor prognosis Other symptoms include diarrhea, shortness of breath Many deaths from secondary infections Severe changes in lung function, renal tubular necrosis, reduced liver function

14. Treatment Basic first aid for victim Primarily supportive treatment Treat pulmonary irritation and maintain adequate ventilation and oxygenation

15. Treatment Oral exposures Administer activated charcoal slurry (240 mL water / 30 gm charcoal) 25 to 100gm in adults and adolescents 25 to 50gm in children ages 1 to 12 years 1 gm/kg in infants less than 1 year old A cathartic may be beneficial

16. Treatment Eye exposure Liquid Extremely irritating May cause permanent damage Gas Irritating Rarely causes permanent injury

17. Treatment Eye exposure Corneal abrasions Mydriatics, systemic analgesics, and topical ophthalmic antibiotics Severe iritis Topical atropine or homatropine

18. Treatment Dermal exposure Extremely irritating Treat topically Dermal hypersensitivity reactions Systemic or topical corticosteroids or antihistamines

19. Treatment Inhalation Oxygen, ventilatory support, and an intravenous line For bronchospasm: inhaled and/or parenteral sympathomimetics, IV theophylline, and steroids Hospitalize and observe all symptomatic patients for 72 hours for possible delayed pulmonary edema

20. Treatment Inhalation Pulmonary edema Maintain ventilation and oxygenation Frequent ABGs or pulse oximetry Control hypoxia with O2 supplementation IPPB, PEEP mask or intubation

21. Treatment Symptomatic patients ECG Chest x-ray Pulse oximetry Peak air flows Arterial blood gases Serum electrolytes Renal and hepatic function

22. Long-Term Medical Sequelae Bhopal accident Chronic eye problems Pulmonary damage Reproductive effects EPA Group D Not classifiable as to human carcinogenicity Teratogenicity not defined

23. Environmental Sequelae Rapidly hydrolyzes when released to moist soil or to water Volatilization from dry near-surface soil or surfaces is likely Bioconcentration, volatilization and absorption not significant processes

24. Summary Difficult to make and safely store Less likely to be a terrorist weapon Immediate danger to life and health by inhalation or oral exposure Eye irritation to full-blown ARDS, and numerous serious systemic effects

25. Summary Supportive treatment Treat pulmonary irritation and maintain adequate ventilation and oxygenation 1984 accidental release in Bhopal, India provides long-term medical consequences data