Final answer:
To scrap a disposable cylinder, the internal cylinder pressure should be reduced to at least atmospheric pressure.
Step-by-step explanation:
The pressure inside a disposable cylinder should be reduced to at least atmospheric pressure in order to safely scrap it. Atmospheric pressure is typically around 1 atmosphere (atm), which is equivalent to 101.3 kilopascals (kPa) or 14.7 pounds per square inch (psi).