Cylinders with water capacities greater than __________ shall NOT be located on decks or balconies of multi-unit dwellings above the first floor.

The correct response regarding the maximum water capacity of propane cylinders that can be located on decks or balconies of multi-unit dwellings above the first floor is 2.7 lbs. This regulation is in place primarily for safety reasons. Propane is a flammable gas, and having larger cylinders on upper floors poses a greater risk in case of a leak or other incident. Smaller cylinders reduce the volume of gas that can accumulate in an enclosed space, thereby minimizing potential hazards associated with gas leaks, explosions, or fires.

By limiting the allowed water capacity to this specific amount, safety codes aim to ensure that the risks are manageable in residential settings, particularly multi-unit dwellings where many people live in proximity to these gas storage cylinders. It is crucial for those involved in propane gas safety and installation to understand and apply these regulations to mitigate risks effectively.