A canister containing an adsorbent material is detachably mounted on a tank truck for delivery of volatile liquids. An inlet to the canister is connected through a vapor recovery hose to the vapor space in a liquid storage tank and an outlet to the canister is connected to the vapor space in a tank on the truck. As the volatile liquid is delivered into the storage tank, air displaced from the storage tank is forced via the vapor recovery hose through the adsorbent and into the delivery tank. Vapors of the liquid are adsorbed in the canister. Pressure relief means are connected to require all air entering or leaving the tank on the truck to pass through the canister.