345 Oxidizing Substances, Organic Peroxides
(Hazard Class 5)

345.1 Definition

Hazard Class 5 consists of two divisions:

1. Division 5.1, Oxidizing Substances: Materials that may cause or enhance the combustion of other materials, generally by releasing oxygen.
2. Division 5.2, Organic Peroxides: Any organic compound that contains oxygen in the bivalent structure and that may be considered a derivative of hydrogen peroxide, where one or more of the hydrogen atoms have been replaced by organic radicals.

Examples of Class 5 materials (not all of which are mailable) include ferric nitrate, hydrogen peroxide, lead perchlorate, lithium nitrate, organic peroxide solids or liquids, and some swimming-pool chemicals.

345.2 Mailability

The following conditions apply for mailing Hazard Class 5 items:

1. International Mail: All oxidizing substances and organic peroxides are prohibited.
2. Domestic Mail via Air or Surface Transportation: Oxidizing substances or organic peroxides that qualify as Limited Quantity air or Limited Quantity surface are permitted.

345.21 Mailable Class 5 Materials

Class 5 materials are permitted for mailing as follows:

1. A division 5.1 or 5.2 material that can be reclassified as a Limited Quantity air or Limited Quantity surface are mailable within the requirements in 345.2(b).
2. Hydrogen Peroxide. Division 5.1 hydrogen peroxide solutions with an 8 percent or less hydrogen peroxide content is regulated as hazardous material but must be prepared according to DMM 601.3.4. Solutions of hydrogen peroxide more than 8 percent but no more than 20 percent are permitted if they can qualify as Limited Quantity air or Limited Quantity surface.

345.3 Packaging, Marking, and Documentation

Labels and text markings must appear on the address side of the mailpiece unless otherwise specified in 221.1 and 325.1. Packages containing mailable Division 5.1 and 5.2 materials must be prepared according to Packaging Instructions 5A in Appendix C and marking as follows:

3. Air Transportation: Packages must be marked with a DOT diamond-shaped limited quantity mark with the symbol "Y" in the center. Refer to Exhibit 325.4b). Each package must also be marked with the proper shipping name, identification number, and an approved DOT Class 5.1 or 5.2 hazardous material warning label. A properly completed Shipper‘s Declaration for Dangerous Goods, prepared in triplicate, must be affixed to the outside of the package.
4. Surface Transportation: Packages must be marked on the address side with an approved DOT Limited Quantity surface marking (refer to 325.4). The Limited Quantity ground marking is sufficient for surface shipments; neither the proper shipping name nor the identification number is required. A shipping paper is also not required for surface shipments of mailable Division 5.1 or 5.2 materials.

Markings must be durable, legible, and readily visible, applied to at least one side or end of the outer packaging. The diamond-shaped border must be at least 2 mm in width, with a minimum side dimension of 100 mm, unless the package size necessitates a reduced marking of no less than 50 mm on each side.

345.4 Nonmailable Class 5 Materials

Nonmailable Class 5 materials that are found in the mailstream and pose an immediate threat to persons or property must be handled in accordance with the procedures in POM 139.117. If no immediate threat is present, refer to POM 139.118.

The following Class 5 materials are nonmailable:

1. Division 5.1, Oxidizing Substances.
1. Chlorine dioxide hydrate, frozen.
2. Hydrogen peroxide solution (more than 20 percent).
3. Perchloric acid.
4. Potassium peroxide.
5. Sodium chlorite.
6. Tetranitromethane.
7. Zinc ammonium nitrate.
2. Division 5.2, Organic Peroxides: Organic peroxides are nonmailable unless they qualify as Limited Quantity air or Limited Quantity surface.