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USPS Packaging Instruction 3A

Flammable Liquids

A flammable liquid having a flashpoint greater than 20° F (–7° C) but less than 100° F (38° C) is mailable in domestic mail via surface transportation, if the liquid can qualify as a consumer commodity or ORM-D material, and all applicable requirements in 343 are met.

Flammable liquids having a flashpoint of 20° or less are not mailable.

Proper Shipping Name

ID Number

Mailability

Required Packaging

Separate packaging requirements apply depending on the flashpoint of the flammable liquid.

For flashpoint greater than 20º F (–7º C) but not more than 73º F (23º C):
Primary Receptacle
Cushioning Material and Secondary Packaging
Outer Packaging
Marking
For flashpoint greater than 73º F (23º C) but less than 100º F (38º C):
Primary Receptacle
Cushioning Material and Secondary Packaging
Outer Packaging
Marking
For flashpoint of at least 100º F (38º C) but not more than 141º F (60.5º C):