Pressure tanks have pressures of

• A. 15 psi or greater
• B. 5 psi or greater
• C. 0 psi
• D. 100 psi

Answer: (A)

The main idea is how packaging is classified by its internal pressure. In hazmat practice, a tank is considered a pressure tank if its design pressure is 15 psi or greater. That 15 psi threshold distinguishes pressure tanks from non‑pressure vessels and triggers specific safety requirements, such as robust shells, pressure relief devices, and careful handling to prevent rapid release. The exact pressure can vary—some tanks operate much higher—but the criterion used for classification is at least 15 psi. The other options don’t fit because 0 psi would be non‑pressurized, 5 psi is still below the threshold, and while 100 psi is a high pressure, the defining rule is the minimum of 15 psi to qualify as a pressure tank.