A method and apparatus for regulating the concentration of a vapor within a hard drive are provided. In one embodiment, the method may include providing a source chemical of a vapor in a first cavity formed within a first object, providing an absorptive chemical which absorbs the vapor in a second cavity formed within the first object, and providing a third cavity formed by a hard drive housing of the hard drive. A first conductance path having a first conductance connects the first cavity to the third cavity, a second conductance path having a second conductance connects the second cavity to the third cavity, and the first conductance and the second conductance maintain a partial pressure level of the vapor within the third cavity.