Propylene oxide was loaded into a rail tank car for temporary storage. In the period before, the rail tank car had been placed on a marshalling yard outside the company fences. It had not been inspected or cleaned before it was brought back on the site. During loading, the man hole cover leaked. The fire brigade found that several bolts were loosened by a few turns.

4 to 5 tonnes propylene oxide were released

Propylene oxide was loaded into a rail tank car for temporary storage. In the period before, it had been cleaned and opened by another company,  for maintenance on the wheels and brakes. Afterwards  the rail tank car had been placed on a marshalling yard outside the company fences. Entering the company fences, the owner company personnel did not take into account that the car had been opened. Propylene oxide was loaded without prior pressure testing. All bolts of the man hole cover were loose (but not visibly loose). As a result propylene oxide was released.

The fire brigade erected a water screen and covered the spilled substance with foam. The fire brigade (in gas suits) tightened the bolts
Response was good. Nearby companies were warned.

Ground pollution was measured, but did not require cleaning up.4,000 Euros: The figure does not include response of the fire brigade (formed by the city of Rotterdam and several companies).Nearby companies were warned.

A contractor company has cleaned and opened the car as instructed and marked it with AIR stickers. Consequently the car was sent to a second company (the owner of the car) for inspection of the wheels and breaks. After inspection the car was returned to the leasing company, accompanied by a standard form indicating that the tank was closed. AIR stickers were still on the tank. The leasing company’s personnel ignored the AIR stickers and started the loading procedure.

It has been the third PO loading incident at this plant in about 1.5 years. Authorities will consult with the company on measures to prevent future incidents.The problem is mainly of communicative nature between the owner and leasing companies. It could be avoided in the future if all rail tank cars were accompanied by a car specific rail book containing maintenance, cleaning and (un)loading records. Furthermore, a rail tank car should not be used for temporary storage, unless additional measures have been taken to ensure the same safety level as a storage tank.The company could have placed more gas detection heads (all around the loading station instead of just at one point).