Would it be safe to travel with approximately pounds of...

Dear Car Talk

Dear Car Talk | Mar 01, 2001

Dear Tom and Ray:

Would it be safe to travel with approximately 50 pounds of dry ice in the trunk of a car over a two- to three-day period? There will be two adults and two pets traveling in the car. -- Karen

RAY: As long as one of the pets is a canary, Karen.

TOM: Actually, it's not safe at all, Karen. When dry ice "melts" (actually, it sublimates -- it goes right from a solid to a gas), it gives off carbon dioxide (CO2).

RAY: And since there's no seal between the trunk and the passenger compartment of your car (the back of your back seat is literally the front of your trunk), before long, you'll be breathing toxic levels of CO2.

TOM: And while CO2 is not as poisonous as carbon MONoxide (the stuff that comes out of your tailpipe), carbon DIoxide IS toxic when it makes up more than a small percentage of the air you breathe -- unless you happen to be a tomato plant.

RAY: And when you breathe too much CO2, you can get symptoms ranging from confusion to breathing difficulties to death.

TOM: None of which make for a pleasant trip.

RAY: So go with a more traditional form of cooling for a long trip, Karen. Use a standard "Coleman"-style cooler and fill it with ice once a day. For two to three days, it's an inconvenience you can live with.

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