page 12 Flashcards
Chloromethane (CH3Cl):
Natural Source: Produced by giant kelp, algae, and volcanic emissions (e.g., Hawaii’s Kilauea volcano).
Environmental Relevance: A major contributor to atmospheric chloromethane originates from natural sources.
Dichloromethane (CH2Cl2)
(Methylene Chloride):
Usage:
Previously used as a solvent in the decaffeination of coffee.
Concerns arose due to potential health risks from residual dichloromethane in coffee.
Now replaced by supercritical
CO2 for decaffeination.
Health Impact:
Studies on rats found no cancer risk even with an intake equivalent to over 100,000 cups of decaffeinated coffee daily.
Halothane (CF3CHClBr):
Medical Use:
A safe general anesthetic that has replaced earlier anesthetics like chloroform (CHCl3 ) and diethyl ether.
Advantages:
Avoids liver and kidney damage caused by chloroform.
Less flammable than diethyl ether.
What are the primary natural sources of chloromethane?
Answer: Giant kelp, algae, and volcanic emissions.
What is the environmental significance of chloromethane?
Answer: Most atmospheric chloromethane comes from natural sources.
What was dichloromethane historically used for in the food industry?
Answer: Decaffeinating coffee.
Why was dichloromethane replaced in coffee decaffeination?
Answer: Concerns about the potential health effects of residual dichloromethane.
What is the current method used to decaffeinate coffee?
Answer: Supercritical
CO2.
What did studies on rats conclude about the health risks of dichloromethane?
Answer: No cancer risk was found even with the equivalent of over 100,000 cups of decaffeinated coffee daily.
What is the main use of halothane?
Answer: A general anesthetic.
Which harmful anesthetics has halothane replaced?
Answer: Chloroform (causes liver/kidney damage) and diethyl ether (highly flammable).
Why is halothane preferred over diethyl ether as an anesthetic?
Answer: Halothane is less flammable.
