We recently got a letter from the USPS Inspection Service stating that we were not shipping some of our hazardous materials with the correct STC (Service Type Code) which after further research is provided on the tracking #/bar code for tracking to help the USPS identify what they may or may not need to do to better handle the package.

We have always handled and labeled our packages correctly to the best of our knowledge. So if we needed extra labeling, we always provided them on hazardous or restricted items/shipments. Again, the STC identifier is provided in the tracking # which we have no control over as we primarily buy shipping labels on Amazon. For example, if the tracking # starts 93001.... the 3rd, 4th, and 5th number are the digits that helps the USPS identify what the STC code is. 001 would be the STC identifier for the USPS in our example above.

001 identifies to the USPS that it is a - USPS Ground Advantage: Up to 15.999oz USPS Tracking

If the tracking started with 93346 -

346 identifies to the USPS that it is a - USPS Ground Advantage: One Pound or More USPS Tracking

When we are shipping hazardous materials on Amazon, we have no control over switching the STC identifier so what are we supposed to do? If we are understanding the USPS's policies and procedures correctly, the USPS states that we would need the STC's to be -

184 identifies to the USPS that it is a - USPS Ground Advantage: Up to 15.999oz USPS Tracking Hazardous Materials

362 identifies to the USPS that it is a - USPS Ground Advantage: One Pound or More USPS Tracking Hazardous Materials

Is this something we can alter or change on Amazon's Buy Shipping? Yes, as the USPS mailed to us, it is our responsibility to know packaging requirements and we have always done our best with what we can research, but this seems to be out of our control here.