Originally Posted by HSVTSO Dean

Well, the aerosols in question have to be flammable, too. It's a matter of hazardous material.
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As far as why they're okay, and those not sprayed onto the body aren't? They're not "okay." They'd still be flammable, they'd still be potentially dangerous. The difference comes, however, because TSA does want people to continue flying
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So, yeah. Personal items are exempt from the flammability requirements of checked baggage. :P