There are many types of explosives, and several ways to classify them. I will be discussing categories and classifications of explosives, which I feel could be relevant to Unturned.
Primary Explosives
Primary Explosives are easy to set off, but generally either have poor characteristics for most purposes, or would be considered unsafe to use in quantity.
Primary explosives are generally only used to set other explosives off. They are used in detonators, mechanical fuses, primers, Maynard tape, percussion caps, rimfire cases, and nipple fire cases.
If primary explosives are in limited supply on a map, it shifts the meta more to one shot kill weapons and flintlock/wheellock/matchlock firearms.
Secondary Explosives
Secondary explosives are inert enough, that they usually rely on primary explosives for ignition.There would be three types of secondary explosives, black powder, smokeless powder, and high explosives.
Black powder and smokeless powder are used to propel projectiles from firearms.
High explosives are used in explosive charges, mines, and projectiles.
Limiting access to black powder and smokeless powder propellants in a map would limit how much power or volume of fire can be used practically.
Limiting access to high explosives in a map would make bases and vehicles more difficult to destroy.
Tertiary Explosives
Tertiary explosives are too inert for a practical quantity of primary explosives to ignite, and are instead ignited by secondary explosives.
Tertiary explosives include ANFO, and many fuels.
To get fuels to ignite into a fiery explosion by being shot by firearms requires such specific circumstances, that it should probably just be considered impossible. If high explosives, or a charge of propellant were used directly on it though…
Tertiary explosives and explosive fuel containers wouldn’t greatly impact the meta, but could be used to make certain locations more interesting, especially if they could be set off by certain NPCs or varieties of Turned, or if setting off a charge of tertiary explosives could allow access to a certain location or progression in NPC quests.
EDIT: I forgot to mention detcord, which can be used for very light demolition (like blasting holes through drywall, or busting weak locks) and for setting off other explosives.
It’s uses are pretty much exclusive to raiding bases and laying traps.