Two months before the explosion in Tiruchi, the Petroleum and Explosives Safety Organisation (PESO) had raised various issues in its safety audit report at the explosives unit, reported The Times of India.

The explosion at the Pentaerythritol tetranitrate (PETN) unit which happened on Thursday, killed 19 people. 

TOI reported that in a letter sent to Vetrivel Explosives Private Limited, PESO wrote that its PETN unit had committed six violations and should immediately follow the recommendations. 

PESO joint chief controller of explosives, Ashok Kumar Yadav told TOI that the PETN unit should not have more than five people as per the rules.

PESO also suspended the license given to the unit. The flaws it stated included a detached plummer block and the uneven oscillation of the shaft in the nitration plant. Moreover, the nitric acid pipeline was hanging without support and in the acid fume tank, the vent pipe was taken out for maintenance and fumes were emanating from the nozzle, reported TOI. 

The unit was asked to have another line with a valve to the filter tank so if the single valve failed, the product could be safely disposed of.

PETN is an explosive used for commercial purposes like quarrying, digging wells, and demolishing civil constructions.

A team of five officials from Chennai, Sivakasi and Vellore on Friday were deputed on Friday to provide technical assistance to the district administration in clearing the debris. Moreover, they wanted to neutralize the huge amount of nitric acid left in the vessel by adding appropriate base like calcium hydroxide. The manufacturer has six other units.