A miscellaneous hazardous material is a substance or article that presents a hazard during transportation but does not meet the definition of any other hazard class.
Miscellaneous hazardous materials include:
- Any material that has an anesthetic, noxious, or other similar property that could cause extreme annoyance or discomfort to a flight crew member.
- Any elevated temperature material, hazardous substance, hazardous waste (other than Division 6.2 medical waste), or marine pollutant.
Examples of miscellaneous hazardous materials (not all of which are mailable) include solid dry ice, primary (non–rechargeable) lithium batteries, magnetized materials, elevated temperature substances, environmentally hazardous substances, life–saving appliances (i.e., automobile air–bags), and asbestos.
349.2 Mailability
- International Mail. All miscellaneous hazardous materials are prohibited, except for certain magnetized materials as permitted in 349.242a and IMM 136g.
- Domestic Mail. A miscellaneous hazardous material that can be reclassed as an ORM–D material and renamed as a consumer commodity is permitted. Additionally, dry ice and magnetized materials are permitted within the specific limits provided in 349.23 and 349.24.
The following materials are prohibited:
- All Class 9 materials that cannot qualify as an ORM–D material, except dry ice and magnetized materials.
- All magnetized materials that have a measurable magnetic field strength greater than 0.00525 gauss at 15 feet.
- For air transportation, all magnetized materials that can cause a compass deviation at a distance of 7 feet or more.
- In domestic mail via air transportation, dry ice in quantities exceeding 5 pounds per mailpiece.
- Primary (non–rechargeable) lithium batteries are prohibited via air transportation.
Primary lithium (non-rechargeable) cells and batteries are mailable via air or surface transportation when the cells or batteries are properly packed with or properly installed in the equipment they operate and the mailpiece has no more than the number of cells or batteries needed to operate the device. All primary lithium cells and batteries must be mailed within a firmly sealed package separated and cushioned to prevent short circuit, movement, or damage. Except for batteries installed in equipment, they must be in a strong outer package. All outer packages must have a complete delivery and return address. Each cell must contain no more than 1.0 gram (g) of lithium content per cell. Each battery must contain no more than 2.0 g aggregate lithium content per battery. Additionally, each cell or battery must meet the requirements of each test in the UN Manual of Tests and Criteria, Part III, and subsection 38.3 as referenced in DOT’s hazardous materials regulation at
49 CFR 171.7. Cells or batteries must be properly installed in the device they operate and must be protected from damage and short circuit. The outside of the package must be marked on the address side “Package Contains Primary Lithium Batteries.” These mailpieces must not exceed 11 pounds. Primary lithium cells and batteries are mailable via surface transportation when the cells or batteries (not packed with or installed in equipment) are in the originally sealed packaging. The outside of the package must be marked on the address side “Surface Mail Only, Primary Lithium Batteries — Forbidden for Transportation Aboard Passenger Aircraft.” These mailpieces must not exceed 5 pounds.
For lithium cells and batteries, the general packaging requirements in DMM 601.1–10 apply.
Secondary lithium-ion (rechargeable) cells and batteries are mailable via air or surface transportation when individual cells or batteries are mailed or when properly packed with or properly installed in the equipment they operate. Cells or batteries properly installed in the device they operate must be protected from damage and short circuit, and the device must be equipped with an effective means of preventing accidental activation. The outside of the package must be marked on the address side “Package Contains Lithium-ion Batteries (no lithium metal).” The mailpiece must not contain more than three batteries. Each cell must contain no more than 1.5 g of equivalent lithium content per cell, and each battery must contain no more than 8.0 g aggregate quantity of equivalent lithium content.
For lithium-ion cells and batteries, the general packaging requirements in DMM 601.1–10 apply.
Dry ice is primarily used to keep other items cool. The items being cooled can be either mailable hazardous materials or nonhazardous items, such as medical specimens or foods.
Dry ice (carbon dioxide solid) is produced by expanding liquid carbon dioxide to vapor and compacting the material into blocks. When dry ice converts (dissipates) to a gaseous form, it takes in heat from its surroundings. The resulting gas is heavier than air and can cause suffocation in confined areas as air is displaced. When dry ice is enclosed in a thick metal or other restrictive type of container, internal pressure builds up and could cause the container to rupture or explode. Mailpieces containing dry ice must be handled with care because its very low temperature (about –110° F
or –79° C) can cause severe burns to skin upon direct contact.
Dry ice is permitted to be mailed when it is used as a refrigerant to cool the content of a mailable hazardous or nonhazardous material. Packages containing dry ice must be packed in containers that permit the release of carbon dioxide gas and conform to 49 CFR 173.217 and 175.10(a)(13). Mailpieces containing dry ice are subject to the following conditions, as applicable:
- International Mail. Dry ice is prohibited.
- Domestic Mail via Air Transportation. Dry ice is permitted in quantities of up to 5 pounds per mailpiece. Mailpieces containing dry ice are subject to the conditions for Packaging Instruction 9A in Appendix C, as applicable.
- Domestic Mail via Surface Transportation. A mailpiece sent via surface transportation (i.e., at Standard Mail rates) may contain more than
5 pounds of dry ice. Mailpiece preparation is subject to the conditions for Packaging Instruction 9A in Appendix C.
Note: A mailpiece that is prepared for surface transportation must not, under any circumstances, be routed via air transportation.
A magnetized material is not classified within any of the nine hazard classes. Such material is regulated as a hazardous material only if offered for carriage on air transportation and when it has a magnetic field strength capable of causing the deviation of aircraft instruments.
A magnetized material is any article that has a magnetic field strength capable of causing the deviation of aircraft instruments. A magnetized material is regulated as a hazardous material when it is presented for air transportation and has a measurable magnetic field strength greater than 0.00525 gauss at 15 feet. Magnetized materials include magnets and magnetized devices such as magnetrons and light meters of sufficient strength to possibly cause erroneous aircraft compass readings. If the maximum field strength observed at a distance of 7 feet is less than
0.002 gauss or there is no significant compass deflection (less than
0.5 degree), the article is not restricted as a magnetized material.
Magnetized materials that have a magnetic field strength of 0.002 gauss or more at a distance of 7 feet from any point on the surface of the outer packaging are mailable via air transportation if properly packaged. Magnetized materials that have a field strength greater than 0.00525 gauss at 15 feet are nonmailable under any conditions. The following requirements also apply:
- International Mail. Magnetized materials are prohibited except for those that cannot cause a compass deviation at a distance of 7 feet or more. See 622.4.
- Domestic Mail via Air Transportation. Magnetized materials that can cause a compass deviation at 7 feet or more are prohibited. A magnetized material is mailable if it is not capable of causing a compass deviation at a distance of 7 feet or more. Mailpiece preparation is subject to the conditions for Packaging Instruction 9B in Appendix C. The address side of the outer packaging must bear the magnetized material warning label shown in Exhibit 349.242b.
- Domestic Mail via Surface Transportation. Magnetized material is not regulated as a hazardous material when transported via surface transportation.
Exhibit 349.242b
Warning Label for Magnetized Materials
For mailable Class 9 materials, the following packaging requirements as detailed in the Packaging Instructions in Appendix C apply:
- Packaging Instruction 9A must be followed for mailable quantities of dry ice.
- Packaging Instruction 9B must be followed for mailable types of magnetized materials.
- Packaging Instruction 9C must be followed for Class 9 miscellaneous hazardous materials that are eligible to be reclassed as mailable ORM–D materials.
- Packaging Instruction 9D must be followed for lithium and lithium-ion cells and batteries.
For air transportation, a mailable Class 9 material that can be reclassed as an ORM-D material must be plainly and durably marked on the address side with “ORM-D AIR” immediately following or below the proper shipping name (Consumer Commodity). A shipper’s declaration for dangerous goods that is prepared in triplicate must be affixed to the outside of the mailpiece.
For surface transportation, a mailable material that can be reclassed as an ORM-D material must be plainly and durably marked on the address side with “Surface Mail Only” and “ORM-D” immediately following or below the proper shipping name (Consumer Commodity).
The specific marking and documentation requirements for dry ice and magnetized materials are specified in USPS Packaging Instruction 9A and USPS Packaging Instruction 9B in Appendix C, as applicable.
