For a Diluent Type B, the diluent’s boiling point must be at least how many degrees higher than the SADT in a 50 kg package?

• A. 5°C
• B. 60°C
• C. 10°C
• D. 30°C

Answer: (B)

A key safety idea is that the diluent must stay non-volatile as the material approaches its self-accelerating decomposition temperature. The SADT is the temperature at which a material may begin to decompose rapidly, generating heat and potentially leading to a dangerous run-away situation. If the diluent boils or vents at temperatures near SADT, internal pressure can build and worsen the hazard, especially in a 50 kg package where the margin for error is small. By requiring the diluent’s boiling point to be at least 60°C higher than the SADT, you create a substantial safety cushion: even if the product heats up toward SADT, the diluent remains liquid and non-volatile, minimizing vapor pressure and reducing the risk of venting, rupture, or intensified decomposition. The other smaller margins would not provide enough protection against vaporization or pressure buildup under realistic heat exposure, so they are not considered adequate.