[pct-l] fuel canister by USPS?

[Lance Marshall]

Anna,
 
Department of Transportation (DOT) rules allow ground transportation of
propane/butane canisters in containers with a capacity of not more than
4 ounces.  They are classified as 'Other Regulated Material - Domestic'.
The package must be marked ORM-D, Consumer Commodity.  This applies to
UPS, FedEx, and other freight haulers.
 
Unfortunately backpacker's fuel canisters don't qualify.
 
Officials recently discovered that MSR canisters had a capacity of 6
ounces although they were filled with only 4 ounces of fuel and
therefore did not qualify for the ORM-D exemption from certain Hazardous
Material restrictions.
 
http://www.outdoorindustry.org/pdf/HazMatExemptionsFuelWN081209.pdf
 
The Postal Service is not bound by DOT regulations although it follows
DOT regulations closely and can even be more restrictive.
 
Postal regulations don't have the same 4 ounce limitation, and therefore
certain small canisters should be mailable by ground as ORM-D.  However,
because of the confusion between DOT and Postal regulations and the
recent revelation about MSR canisters, you might find that your local
post office won't accept the canisters for ground mail.
 
Air transportation is an absolute no.
 
Good luck!