Hydrogen Sulphide incident

Two workers have died in a paper mill in Australia due to likely exposure to hydrogen sulphide gas while working on top of a water tank. It is reported that the mill was under maintenance and most probably a decomposition of the pulp in water formed hydrogen sulphide. The mill had an excellent safety record but yet this happened. Dont even let your guard down,

Batch Reactor incidents

1. During trial batch on plant & completion of solvent & acid addition, heating was started. After 15 min. pressure increase observed on reactor. Solvent vapours came out through flange joints of reactor and resulted in explosion due to electrical spark resulting in three fatalities. Root Causes: Non-flameproof electrical installations an Hazard identification & Risk assessment & control was inadequate. 
2. Reactor pressurised due to exothermic reaction containing oleum & solvent. The mixture came out from reactor manhole.Two workers working below the reactor were injured due to splashing of acid & during treatment they died. Root Causes: High rate of oleum addition due to failure of orifice. Hazard and operability (HAZOP) study and interlocks were not appropriate. 
3. In a batch reactor, chlorination was started at 9.00 p.m. Approximately 300 Kgs chlorine was passed. Reactor was containing intermediate chemicals. At about 10.30 p.m, release of toxic gas from scrubber vent was observed. Employees of near by industries were affected by inhalation. Root Causes: Failure of scrubbing system, Leak detectors & alarms were not in operation. 
4. During addition of solvent in agrochemicals intermediate kettle, toxic & poisonous gas started releasing from flange joints. Shop floor workers affected due to inhalation of poisonous gas. Two fatalities & three injured. Root Causes: Hazard not identified & risk was not evaluated before starting the batch. Improper MOC of gasket, No proper scrubbing system.

Courtesy: A.G.Shingore, National Safety Council

Lessons learnt from Ammonia release incident

https://www.techsafetygroup.com/lessons-learned-anhydrous-ammonia-release-incident/

Human error and Human factor incident

Reaction containing flammable mixture was completed. The batch was transferred to another kettle. Inerting was carried out. As soon as the nitrogen gas was admitted, an explosion took place in the system. Two operators were killed & five injured. Root Causes: Instead of inert gas, air was admitted, by mistake. There was no system to ensure the specific inert gas or air in the cylinder.

Courtesy: A.G.Shingore, National Safety Council