More than 75% of the tank storage firms currently operating the Netherlands are not complying properly with the rules, according to research by the social affairs ministry.

Inspectors looked at 91 firms which store dangerous and inflammable chemicals in overground tanks and found problems at 73. Most of the 323 infringements of the law were not considered serious but at four the situation was so dangerous, immediate action was taken, the report said.

The inspections were carried out in the wake of the lax safety standards at the Odfjell site in Rotterdam. Among the problems identified by inspectors last year were a shortage of fire-fighting equipment, poor safety procedures, and staff being over-exposed to the chemical benzene.

None of the new findings were as serious as the Odfjell situation but did give rise to concerns about attitudes to safety issues, the inspectors said.