At a rubber factory, an explosion occurred inside a lubricant container filled with 18 tonnes of tri-(nonylphenyl) phosphite (TNPP or TNPA). This tank was typically stirred and maintained at 45°C; moreover, the heating circuit routed to the container had broken down 7 days earlier. With the polluted TNPP scheduled for disposal, the accident occurred during a sawing operation to remove the walkway interfering with the manhole opening. The TNPP substance underwent hydrolysis in contact with water leaking via the broken coil; the resultant phosphoric acid corroding the steel on the container caused hydrogen to form. The relatively slow hydrolysis reaction was no doubt catalysed by metal particles (rust, etc.). A technician was seriously injured due to a fall. The new installation would obviously be ventilated and protected from rainfall or any other potential water intake. A heating belt (with Tmax < T° of TNPP degradation) replaced the coil, and a posted instruction reminded workers of the product's sensitivity to water.