the storage of alkanes depends on the chain length, as the chain length increases or decreases so does the volatility due to the dispersion forces:
the main safety issues associated with the storage of alkanes is the fact that they are highly flammable. This means that the bonds are had to break and have a large amount of kinetic energy, resulting in a high flammability and large release of energy when combustion occurs. Alkanes are also highly volatile and therefore combust easily. Alkanes also have flashpoints below room temp so if exposed to a naked flame will combust easily.
Therefore alkanes must be stored as liquids as they cannot combust at a liquid state.
The low polarity of the bonds of hydrocarbons means that the only intermolecular forces between molecules are very weak and as a result hydrocarbons have very low melting and boiling points. This relates to volatility- as alkanes hav relativly low mp/bp they are more likely to change from a liquid to a gas more easily and therefore combust more easily, hense the importance of storin them as a liquid as combustion can only take place when in a gaseous form. When stored under prssure or in a cool place they are not going to turn into a gas as easily so stored in a cool place as a liquid is the best way to store them.......
hope this helps