Pollution
Humain
Environnement
Economique

An explosion and fire occurred in a 10-story mixed-occupancy building in Manhattan, injuring 36 people including 6 firefighters and 14 members of the public. The building was extensively damaged and the street remained closed for 2 weeks.

The incident originated in the basement, in a space leased by a metal signs and letters manufacturer, just after employees had finished consolidating hazardous waste (mainly spent etching solution, an aqueous mixture of ferric chloride, ferrous chloride, hydrochloric acid, and solubilized metals) from smaller containers into two larger drums for shipment off site to a waste treatment firm. Most of the waste containers were not labelled and the employees, insufficiently trained, did not know the identity of the materials, their hazards, or their compatibility with each other. They mistakenly believed all the drums contained the same type of waste and mixed them in 200 L plastic drums. However, one drum contained nitric acid, a strong oxidizer incompatible with organic substances. The mixing od incompatible chemicals lead to the explosion.

The operator could not recall using nitric acid : it likely that the nitric acid, which can be used in some metal etching processes, had been obtained at one time and subsequently forgotten, left in an unlabeled container.

The US CSB made recommendations regarding labelling of dangerous substances and waste, personnel training, availability of safety data sheets and written instructions, safe storage and handling practices (separation of incompatible materials…), and a common safety organisation for mixed-occupancy buildings.