A small quantity is the maximum amount of a specific hazardous material that is not subject to any DOT requirements (e.g., packaging, marking, labeling) other than those in 49 CFR 173.4. Not every hazardous material is eligible to be shipped as a small quantity. Additionally, for Postal Service purposes, Class 7 materials are not permitted to be sent as a small quantity.
The DOT small quantity provision, like the DOT ORM–D category, is unique to the United States. Its use is prohibited with international shipments of hazardous materials and cannot be used in international mail.
Hazardous materials in Class 3, Division 4.1, Division 4.2 (Packing Groups II and III only), Division 4.3 (Packing Groups II and III only), Division 5.1, Division 5.2, Division 6.1 (Packing Groups II and III only), Class 8, and Class 9 are eligible to be sent in the domestic mail under the small quantity provision only when each primary receptacle is limited to the following quantity, as applicable:
- 30 ml (1 oz) or less for liquids other than Division 6.1 (Packing Group I) materials.
- 30 g (1 oz) or less for solids other than Division 6.1 (Packing Group I) materials.
- 1 g (0.04 oz) or less for Division 6.1 (Packing Group I) materials.
Hazardous materials eligible to be shipped under the small quantity provision permitted in 49 CFR and 334.2 must be prepared following Packaging Instruction 10A in Appendix C. Each mailpiece that qualifies to be sent under the small quantity provision must be clearly marked on the address side with the following words: “This package conforms to 49 CFR 173.4.”