How to Ship HAZMAT with USPS

USPS now requires shippers to formally declare when their parcel contains a hazardous item. This declaration is required at the time of label purchase. There are no exceptions to this requirement and shippers are expected to ensure they remain in compliance at all times. 

In addition, USPS requires a clear separation of HAZMAT and non-HAZMAT items into separate, identifiable packages or mail receptacles. All parcels containing hazardous materials need to be marked as hazardous.

Creating a HAZMAT Shipment

At Shippo, we've made this process as simple as possible. When creating your order in the web app, indicate a shipment as containing hazardous materials, and we will ensure your label reflects this.

Web App Users

Web App users can designate that a shipment contains hazardous materials on the Orders page:

  • Select the Order or create a new one. 
  • Then, from the side panel, navigate to the Package options section.
  • Select Shipment contains hazardous materials.
  • Then, click Save.






  • We only allow the hazmat selection for USPS (this does not apply to other carriers). When you select this checkbox, we will refresh rates and only show applicable USPS service levels. If a sender's address is not in the US, the option will be disabled.
  • For domestic hazmat shipments, USPS only offers ground transportation. For example, if you indicate "shipment contains hazardous materials", you will not see rates for Priority Mail or Priority Mail Express.
  • It is possible to bulk select US orders and indicate "shipment contains hazardous materials", however, if a mix of US/non-US or only non-US orders are selected, this shipping option will be disabled.


API Users

API users can add the "dangerous_goods" shipment extra for label purchases to facilitate shipping hazardous materials. Please refer to our API reference documentation for more information.


What is Considered HAZMAT?

Assigned by the U.S. Department of Transportation (DOT), hazardous materials are any items that are capable of posing an unreasonable risk to health, safety, and property during transportation. For international shipping, these items are often referred to as “dangerous goods”.

The most common types of items that fall into this category include:

  • Articles containing liquid mercury (such as thermometers, barometers, and blood pressure equipment)
  • Lithium batteries (or any electronics that include lithium batteries such as cell phones and laptops)
  • Aerosols (such as hairspray, disinfectants, and spray paint)
  • Fragrances (such as colognes, perfumes, and body sprays)
  • Dry Ice (which can be used to preserve temperature-sensitive items such as food and medicines)
  • Paint, Paint Thinners, and Removers (wood stains and adhesives would also fall into this category)
  • Nail polishes and nail polish removers
  • Fuel or fuel-powered machinery (this could include gas lanterns, camp stoves, model cars, or even lawn equipment.)

Please note that the list above is not entirely inclusive. In addition to these examples, there are thousands of other items that could fall under the umbrella of HAZMAT. You can use the HAZMAT Search Tool via the USPS website to find which category your item falls under. It is your responsibility as a shipper, to ensure your items are appropriately categorized at all times. 


USPS Lithium Battery Exception for Domestic Shipments

For domestic shipments that contain new electronic devices, in original unopened packaging or manufacturer-certified new or refurbished devices, that are not required to, and do not bear a lithium battery marking are exempt from applying service type codes and extra service type codes.

These packages must meet the following criteria:

  • only button cell batteries installed in equipment; or
  • no more than 4 lithium cells; or
  • 2 lithium batteries installed in the equipment they operate, (i.e., cell phones, tablets, digital readers, glucose monitors, etc.); or
  • when there are no more than two mailpieces in a single consignment, per Pub 52, Section 34

Please note that this exemption does not apply to packages being sent internationally.


How Shipping Hazardous Materials with USPS Works

In order to safely ship hazardous materials with USPS, you’ll need to follow four steps.

Step 1: Find the Safety Data Sheet (SDS)

A safety data sheet is a standardized document that contains information on your product such as the chemical composition, health and environmental hazards, protective measures, and safety precautions for storing, handling, and transporting the product.

In order to obtain the SDS, you’ll need to visit the product manufacturer’s website or contact them directly. Once you’ve obtained the SDS, you’ll want to save the information provided for transporting the product.

Step 2: Find Shipping Instructions

Using tools such as Publication 52 and the USPS’s HAZMAT Tool can help you identify if a product is allowed to be shipped via USPS, what service levels it is restricted to, and how to properly package the product and label the parcel. You’ll need information that is found in the SDS in order to ensure you’re looking at the right instructions.

Step 3: Follow Marking and Labeling Requirements

Not every Hazmat item uses the same warning label. There are dozens of USPS HAZMAT markings so be sure you’re using the correct one before handing off the parcel to them.

Step 4: Package, Label, and Ship Product

You’ll need to be sure that your item is sealed in accordance with Appendix C of Publication 52. For example, this may include sealing any liquids in multiple containers to avoid any leakage.

You’ll then need to then ensure DOT HAZMAT labels are the proper size and attach that on the same side of the box as where you decide to place your shipping label.

When you’re ready to make your shipping label, you must select “Shipment contains hazardous materials” within the Shippo web app before you purchase a USPS label. You’ll find it under the “options” drop-down within the side panel of your Orders page.



If you know your item is considered hazardous, simply click on the button and then select save. This ensures that your shipping label reflects that you’re shipping a HAZMAT good, allowing the Postal Service to automatically identify the item and handle the package accordingly throughout its journey.

Keep in mind that if HAZMAT is indicated for the package, returned services will be restricted. For both web-app and API users, only Ground transportation would be available (Priority Mail and Priority Mail Express would not be). Also, once this option has been selected, international USPS services will not show up as an option and neither will domestic services that may involve planes such as Priority Mail or Priority Mail Express. This is to ensure that you’re complying with USPS HAZMAT requirements.




  • When using recycled boxes as your packaging, you need to remove all outer stickers that no longer pertain to the current shipment. For example, if a previous package contained an item with a lithium battery and required specific stickers, it’s essential to remove those labels when reusing the box for a non-HAZMAT item.
  • Carriers including the USPS are leveraging technology to ensure the shipping label information and packaging HAZMAT labels match the contents within the package to ensure a safe, smooth delivery process and prevent your package from being delayed. Packages shipped with HAZMAT stickers, but have a shipping label that does not state HAZMAT may be delayed.
  • Effective October 1, 2023, the United States Postal Inspectors have the authority to assess civil penalties for Hazmat violations per incident. Shipping improperly prepared, undeclared, or prohibited HAZMAT can result in civil and criminal penalties under federal law. To learn more, refer to Poster 318 - Civil Penalty Notice.
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