DAHEJ PLANT FIRE REPORT

YASHASHWI RASAYAN PRIVATE LIMITED DAHEJ INCIDENT REPORT

DESCRIPTION OF THE INCIDENT

As per the information received, the Incident happened due to the mixing of Dimethyl Sulphate and Concentrated Nitric Acid. Nitric acid tanker unloaded in the tank of Dimethyl Sulphate by mistake on 02.06.2020.

Management decided to tackle this emergency on the next morning, till that they were spraying water on the tank continuously to control the temperature. The explosion was so severe that the RCC building of the plant observed cracks. Nearby village Luvara evacuated to a safe place immediately after this incident.

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The incident resulted in death of 8 people and 40-50 injured.

On 03.06.2020, they decided to dispose of the material by taking out it in tankers. Before taking a mixture of Dimethyl Sulphate and Nitric Acid in the tanker, they started circulation through an unloading pump as per the senior’s instruction. During circulation, within no time the tanker exploded. Hydrogen trolleys were standing near to this tanker and hydrogen also caught fire and exploded.

POSSIBLE CAUSE AND CONTRIBUTING FACTORS

Medium

• Mixing of nitric acid with dimethyl sulfate which is incompatible with each other.
• Dimethyl sulfate reacted exothermically with nitric acid resulting in an increase in the pressure in the tank which caused the explosion.

Man

• The workers failed to identify the tank of nitric acid. The casual approach of management is work from contract workers
• The workers did not know that nitric acid and dimethyl sulfate were incompatible and should not be mixed.

Management

• Hydrogen trolley was kept near the storage tank farm.
• Failed to handle the incident. (Did not treat as an emergency)
• Evacuation not done before starting the scenario handling.
• The management failed to carry out a thorough Hazard and Operability (HAZOP) study and a Quantitative Risk Assessment (QRA) on the tank and associated process lines.

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Casue Analysis

Evaluation of Loss	8 workers died and 40-50 were injured.
Immediate cause	mixing of Dimethyl Sulphate and Concentrated Nitric Acid.
Basic cause	Dimethyl Sulphate and Concentrated Nitric Acid are incompatible with each other.
Failure to EHSMS	• Process safety information • Hazard identification, risk assessment, and risk control • Plant layout • Operating procedures and safe work practices • Training, awareness and competence • Control of hazardous substances • Emergency preparedness and response

Recommendations and Learning Points

• Carry out a risk assessment prior to any work involving hazardous chemicals and develop safe work procedures to include all control measures used to address the identified risks.
• Provide competency training to ensure that the workers understand the process flow and the risks associated with the mixing of incompatible chemicals.
• Skilled manpower in hazardous process
• Ensure positive isolation of process lines through the use of double block valves and bleed with spading to prevent accidental mixing of incompatible chemicals.
• Proper implementation of recommendations of the plant siting and layout.

What we can do

• Hazard identification, risk assessment, and risk control
• Plant siting and layout
• Employee selection
• Operating procedures and safe work practices.
• Follow the tanker loading and unloading permit.
• Control of hazardous substances by following the Chemical Management Plan.
• Emergency preparedness and response.
• Training, awareness, and competence.

Credit for this incident report:

Shailendra (Safety professonal) HSE whatsapp group.