Final answer:
The question seems incomplete, but generally addresses regulations for the transportation of flammable liquids by aircraft, which are likely related to labeling, packaging, or quantity restrictions. The warning on the can indicates a safety concern related to increased pressure at higher temperatures, which is explained using the ideal gas law.
Step-by-step explanation:
An overpack containing four one-liter metal cans of Compound, cleaning liquid, a class 3 (flammable liquid), PG I, being offered for transportation by aircraft, does not require a specific answer since the question seems incomplete. However, such liquids typically have regulations that mandate labeling, packaging, and quantity restrictions when transported by aircraft. The incomplete sentence possibly refers to these regulations, which might include exemptions based on the quantity or specific packaging instructions.
As for the additional information provided regarding the storage of the cans, the warning to "Store only at temperatures below 120 °F (48.8 °C). Do not incinerate." is likely due to the increase in pressure that can occur when the contents are heated, as gases expand when warmed, which can lead to an explosion if not properly stored. Applying the ideal gas law (PV=nRT), we can predict the pressure changes under different temperatures. If the gas in the can is initially at 24 °C and 360 kPa, and the can has a volume of 350 mL, when the temperature rises to 50 °C, the new pressure can be calculated assuming the amount of gas and the volume remain constant.