The railway staff noticed five litres of methanol leaking from a tanker drawn outside the sender company 48 hours after being filled. The leak occurred at one of the lateral plugs of the tanker’s drain pipe that was not correctly secured. The plug was screwed back properly and the tanker sent back to the sender company to be emptied. The accident occurred due to the failure of three cut-off elements assembled in series (poor tightness of the operating spindle at the bottom even though leaded, insufficient tightness/closing of the control valve and poor tightening/degradation of the safety plug joint. The operating modes were checked and the various players involved were briefed on the same, the checks on tankers leaving the company were tightened and customers were made aware on the need to regularly inspect the state of their tanks.