Which method is prohibited for shipping an XRF device?

Shipping an XRF (X-ray fluorescence) device through the United States Postal Service (USPS) is prohibited primarily due to the potential hazards associated with the device's function and the regulatory environment surrounding materials that emit radiation. XRF devices often contain radioactive sources and are used for various applications, including testing for lead in paint and soil, which raises safety and security concerns during transit.

USPS has strict regulations regarding the shipment of hazardous materials and devices that may emit radiation. The limitations are in place to protect postal employees and the public from exposure to harmful radiation and to ensure that these devices are handled and shipped in compliance with federal laws and regulations. Therefore, shipping an XRF device via USPS is not permissible.

In contrast, other shipping services like FedEx, UPS, and certain courier services have their own guidelines and criteria for shipping hazardous materials, including XRF devices, which can often accommodate such shipments under strict compliance with safety regulations. This flexibility allows these companies to manage the associated risks more effectively than USPS.