Postal Explorer > Publication 52 - Hazardous, Restricted, and Perishable Mail > Appendix C USPS Packaging Instructions for Mailable Hazardous Materials > USPS Packaging Instruction 2A

USPS Packaging Instruction 2A

Flammable Gases

A Class 2 flammable gas that qualifies as an ORM-D material is mailable provided that all applicable requirements in 342 are met and it is properly packaged as follows.

Proper Shipping Name

• Consumer Commodity.

ID Number

• Various (see Appendix A).

Mailability

• International Mail: Prohibited.

• Domestic Mail: Permitted only via surface transportation sent as Standard Mail or Parcel Post.

Required Packaging

Primary Receptacle

• The capacity of an other-than-metal (nonmetal) primary receptacle must be 4 fluid ounces (7.22 cubic inches) or less per mailpiece.

• The capacity of a metal primary receptacle must be 33.8 fluid ounces (1-liter or 61.0 cubic inches) or less per mailpiece.

• The liquid content of the material and the gas must not completely fill the primary receptacle at 130? F.

• A DOT 2P container must be used if the internal pressure is from 140 psig to 160 psig at 130? F (55? C). A DOT 2Q container must be used if the pressure is from 161 psig to 180 psig at 130? F (55? C).

• A container with an internal pressure more than 180 psig at 130? F (55? C) is prohibited from mailing.

• Primary receptacles must have recessed valves, screw-thread caps, tap closures, or other means to prevent accidental discharge. Valves and fittings must be protected to ensure the integrity of the receptacle during transport.

Cushioning Material

• Sufficient cushioning material must surround the primary receptacle to absorb shock and prevent damage.

Outer Packaging

• Strong outer packaging that is capable of firmly and securely holding the primary receptacle and cushioning material is required.

• Multiple primary receptacles may be securely packed within a single strong outer packaging, provided the total volume of flammable gas does not exceed 33.8 fluid ounces (1 liter) per mailpiece.

Marking

• The address side of the outer packaging must be clearly marked with "Surface Only" or "Surface Mail Only" and "Consumer Commodity ORM-D."

• A complete return address and delivery address must be used.