Heptanoic Acid is an organic compound composed of seven-carbon chain terminating in a carboxylic  acid. It is an oily liquid with  an unpleasant, rancid odor. It contributes to the odor of some rancid oils.
n-Heptanoic acid is used primarily:
In the form of esters: industrial lubricants (aviation, refrigeration, etc.),
Plasticizers for laminated glass, tracer for butter etc.
In the form of salts: for aqueous anticorrosion.
As raw material for perfume, medicine and lubricating grease.
As chemical intermediate in the synthesis of emollient agents:
In personal care: propylene glycol diheptanoate & stearyl heptanoate
In pharmaceutical gel: neopentylglycol diheptanoate.