An excepted quantity refers to a defined amount of a specific hazardous material that is eligible for transport aboard passenger aircraft and is exempt from most DOT requirements (e.g., packaging, marking, labeling) under 49 CFR § 173.4a. For Postal Service purposes, Classes 1, 2, 4, and 7 and Division 6.2 materials are not permitted to be sent as excepted quantity. The excepted quantity provision is applicable to domestic mail only, and its use is prohibited for international shipments or APO/FPO/DPO mail. The excepted quantity provision can be used in domestic air or surface transportation (highway, rail, or vessel).
Only materials authorized for transport aboard passenger aircraft in accordance with 49 CFR § 172.101 and appropriately classed within one of the following hazard classes or divisions may be mailed as an excepted quantity. These include:
- Class 3 (Packing Groups II and III).
- Division 5.1 (Packing Groups II and III).
- Division 5.2 (but only when contained in a chemical kit, first aid kit, or polyester resin kit).
- Division 6.1 (Packing Group III).
- Class 8 (Packing Groups II and III, except for UN2803 (Gallium) and UN2809 (Mercury)).
- Class 9 (excluding UN1845 (Carbon dioxide, solid, or dry ice) and lithium batteries).
Materials identified in column (b) of Appendix A as forbidden are ineligible for mailing under the excepted quantity provision, regardless of their hazard class, division, or packing group.
The maximum amount of hazardous materials allowed in each inner (primary) packaging is as follows:
- 30 g (1 ounce) for solids.
- 30 ml (1 ounce) for liquids.
The total amount of hazardous materials per mailpiece is limited to:
- 500 g (1.1 lbs.) for solids or 500 ml (0.1 gallon) for liquids in Packing Group II Class 9 materials, or Division 5.2 materials.
- 1 kg (2.2 lbs.) for solids or 1 liter (0.2 gallon) for liquids in Packing Group III.
Eligible hazardous materials shipped under the excepted quantity provision must adhere to 49 CFR § 337.2 and Packaging Instruction 10B in Appendix C. Mailpieces under the Postal excepted quantity provision must meet the package tests requirements in 49 CFR § 173.4a and include the DOT-approved excepted quantity marking (refer to 221.1 and 325.6). When applicable, include documentation as provided in 49 CFR § 173.4a(h).
