PROCESS SAFETY MANAGEMENT INDIA

September 8, 2022

Asphxiation incident

Employees were tasked to fill a series of Chart MVE 1842P-150 Cryogenic Freezers in an enclosed storage room on a weekly basis. The room was not equipped with an adequate engineered ventilation system or oxygen monitoring equipment or system. On the evening of November 20, 2019, an employee began topping the bulk tanks off with liquid nitrogen when the room became filled with nitrogen gas causing the employee to collapse and eventually succumb to the oxygen-deficient atmosphere created in the room. The room was not equipped with an adequate engineered ventilation system or oxygen monitoring equipment or system. This condition exposed an employee to an oxygen deficient atmosphere while filling bulk tanks with liquid nitrogen.

Source:OSHA.gov

September 4, 2022

Decomposition incident

On September 21, 2003, Employee #1 and several coworkers were working at a chemical plant that deals with nitric oxide. On the day of the accident, a major leak occurred in a stainless steel distillation column. The nitric oxide leaked into the facilities surrounding vacuum jacket and into the atmosphere through a pump, which controls a high quality vacuum inside the jacket to minimize transmission of heat toward the cryogenic distillation columns. A brown cloud quickly formed and the temperature and the pressure inside the distillation column and its surrounding vacuum jacket began to rise. The leak was detected and the vacuum pump was turned off to halt the leakage of nitric oxide into the atmosphere, allowing the pressure inside the column and vacuum jacket to stabilize around 130 psi. Although stabilized, the pressure was far above the normal pressure of less than or equal to atmospheric pressure (14.7 psi). Approximately 3 hours later, an explosion occurred. The operation and process were destroyed, and debris flew through the plant. Employee #1 suffered lacerations due to flying glass and was treated at a local hospital, where he received stitches and then released. A detailed investigation determined that the cause of the explosion was most likely due to something inside the vacuum jacket initiated the dissociation of nitric oxide, a reaction that is very rapid, exothermic, and self-propagating once started.

Source:Ohsa.gov

August 31, 2022

HAS YOUR HAZOP STUDIED THIS POSSIBILITY?

On April 2, 2003, Employee #1 and a coworker, the technicians, were watching a polymerization process involving styrene and acrylonitrile monomers. Employee #1 and the coworker's jobs involved monitoring a reactor vessel throughout the process. At the end of the batch process, non-polymerized monomer and vapors were stripped from the reactor through a condenser system to a distillate collection tank and were ultimately charged to subsequent batches. Toward the end of the stripping process, Employee #1 left the control room to determine if enough distillate had been removed to allow the remaining water and mixture to be dumped to the "dirty" sewer and a collection system. While Employee #1 was in the vicinity of the reactor, an explosion occurred in a small auxiliary charge tank. A piece of metal struck Employee #1's abdomen and killed him. Although the charge tank was not in use at the time of the accident, a small amount of the batch had back-flowed through a valve between the reactor and the auxiliary tank during the reactive process. The batch continued to react in the auxiliary tank, overheating and overpressurizing the tank.

Source:Osha.gov

August 27, 2022

WHERE DO YOUR RUPTURE DISCS VENT?

Employee #4 was cleaning the #6 chemical reactor on July 19, 1990, with a flammable mixture of solvents when the reactor burst its rupture disc and the mixture was expelled into the plant. The solvent ignited and the vapor cloud explosion resulted in the plant's 43 employees being injured by flying debris and/or being thrown by the force of the explosion. Employee #4 eventually died from his burns. Employee #1, a maintenance employee, was moving away from the area when he was struck in the head and killed by debris flung during the explosion.

Employees #3, #6, #7, #8, #9, #16, and #19 were located in the manufacturing offices in Building 4, about 75 ft south of the reactor. Employees #2, #10, #11, #12, #14, #15, and #17 all worked in Building G, 50 to 75 ft southwest of the reactor and were leaving when the explosion either threw debris at them or threw their bodies onto equipment or debris. Employee #5 was in the same building as the reactor and was thrown down by the explosion, sustaining burns and crushing injuries. Employee #13 sprained his knee while moving from the break room to the courtyard, about 100 ft southeast of the reactor. Employee #18 suffered a sprained left thigh and a bruised shoulder.

It appeared that the reactor was not vented to a safe location and had primitive temperature controls, and the company did not enforce the mandatory attendance of operators at the reactors during operation. All of these factors, including minimal operating procedures (none specifically for cleaning), led to the explosion and the resulting extensive injuries and property damage.