These are fuel handlers coveralls used by the US Military. The coveralls protect the wearer from potentially dangerous liquids contacting their skin or clothes, such as JP-8 fuel. The coveralls are made of GORE-TEX, which keeps the wearer protected and dry while still breathable. There are multiple pockets and zippered armpits. The legs are also zippered at the cuffs so that they can be taken on and off while wearing boots easily. The coveralls include and fold away hood.
These coveralls are NOT flame retardant and should not be used close to flames or fire.