An 80-litre leak of fuel oil through the vent of a tank being filled in a hydrocarbon depot spilled onto the road. The depot’s manager intervened by using absorbent products to recover the spilled products. The delivery driver did not check if the tank was in fact able to receive all of the product delivered and the tank’s vent was masked by another vehicle waiting delivery. The tanks at this installation are equipped with overfill protection devices but unit on the tank in question was faulty. Finally, the spilled products should have been directed to a retaining basin in the installation, demonstrating the installation’s faulty design. The Classified Installations Inspectorate recorded the facts.