aerosol shipping international physics
May 5, 2006 12:31 PM Subscribe
I want to send a can of Gruv Glide from Los Angeles to Sweden via air post. Would an aerosol can explode during shipping?
It may. Aerosols shouldn't go on aircraft without special packaging. Any pressurized cylinder, including spray cans, is a Dangerous Good. If you don't declare it and it explodes in flight, you are liable for damages (and the air carrier will be really, really pissed). If you package as a dangerous good (phone these people for free advice on shipping), the carrier takes liability for transport.
posted by bonehead at 12:58 PM on May 5, 2006
posted by bonehead at 12:58 PM on May 5, 2006
Let's see, this question has been asked in regard to:
bicycle tires
thermarest
A plane, including the cargo hold, is pressurized. The pressure drop is only five psi, at most. Aerosol cans are designed to not explode anywhere on earth, and earth includes places which have less pressure (at ground level, out in the open, but way higher than sea level) than an airplane cargo hold. So it WILL NOT EXPLODE.
However, airlines have rules against shipping pressurized things anyway. Your choices are: ship it without telling the postal company (bad socially, but won't have any bad results), or ship it as hazardous material (very expensive), or ship it surface mail.
posted by jellicle at 1:26 PM on May 5, 2006
bicycle tires
thermarest
A plane, including the cargo hold, is pressurized. The pressure drop is only five psi, at most. Aerosol cans are designed to not explode anywhere on earth, and earth includes places which have less pressure (at ground level, out in the open, but way higher than sea level) than an airplane cargo hold. So it WILL NOT EXPLODE.
However, airlines have rules against shipping pressurized things anyway. Your choices are: ship it without telling the postal company (bad socially, but won't have any bad results), or ship it as hazardous material (very expensive), or ship it surface mail.
posted by jellicle at 1:26 PM on May 5, 2006
In fact, at 35,000 ft, ambient pressure is 3-4 psi, so you're looking at a drop of about 10 psi.
Cans are supposed to be good to 180 psig (ie above ambient). Typical cans won't fail until well over 300 psig, so 10 psi shouldn't make a difference. Cans have failed well below even the 180 psig mark, however. When they do fail, they can go off like a small bomb. This is why air carriers don't like shipping them bare.
Risk is a consideration of both chance and consequence. The concenquences here could be very severe, so the air carriers don't want to take even a small risk. It's their plane, they get to set the rules.
posted by bonehead at 2:17 PM on May 5, 2006
Cans are supposed to be good to 180 psig (ie above ambient). Typical cans won't fail until well over 300 psig, so 10 psi shouldn't make a difference. Cans have failed well below even the 180 psig mark, however. When they do fail, they can go off like a small bomb. This is why air carriers don't like shipping them bare.
Risk is a consideration of both chance and consequence. The concenquences here could be very severe, so the air carriers don't want to take even a small risk. It's their plane, they get to set the rules.
posted by bonehead at 2:17 PM on May 5, 2006
bonehead: The cargo hold and the rest of the plane are pressurized. Like I said. The pressure differential is no more than 5 psi. Talking about the pressure outside at 35,000 feet is valid if and only if the cargo is going to be flown outside the body of the plane, which it isn't. Why doesn't anyone understand this or even read the numerous comments saying it?
posted by jellicle at 3:18 PM on May 5, 2006
posted by jellicle at 3:18 PM on May 5, 2006
jellicle, you are correct in a normal situation. But what happens when there is a catastrophic de-pressurization due to some accident or error? Suddenly you have a potential for explosion that did not exist before.
I think it is not honest to talk about cargo holds as non-dynamic in the real world. Lots can happen.
posted by qwip at 5:50 PM on May 5, 2006
I think it is not honest to talk about cargo holds as non-dynamic in the real world. Lots can happen.
posted by qwip at 5:50 PM on May 5, 2006
This thread is closed to new comments.
posted by pmbuko at 12:40 PM on May 5, 2006