Explained: The deadly dust that triggered Telangana's Sigachi factory explosion

Time of India

23-07-2025

New Delhi: A major explosion at a
pharmaceutical facility
in Pashamylaram, Sangareddy district of Telangana, claimed 44 lives, left 17 injured and 8 missing, according to official and news sources. The incident occurred on June 30, 2025, at the Microcrystalline Cellulose (MCC) drying/reactor unit of M/s
Sigachi Industries
Private Limited.
Preliminary findings indicate a
dust explosion
triggered by a suspected
pressure build-up
in the spray dryer or air-handling system. Early investigations point to overheating, malfunctioning temperature sensors and alarms, and failures in safety instrumentation and monitoring.
A dust explosion is caused by rapid combustion of fine particles suspended in the air in an enclosed environment. The explosion at the Sigachi unit involved MCC – a combustible particulate commonly used in pharmaceutical formulations.
'Overheated spray dryer due to inadequate airflow control and possible air handling system malfunction appears to be the primary trigger,' stated the case study by PNGRB. Other contributing factors include faulty sensors, ineffective alarms, and inadequate maintenance.
Dust explosions generally require five conditions: fuel (
combustible dust
), oxidiser (air), dispersion (turbulence), confinement, and an ignition source such as hot surfaces or static electricity. The combination of these factors can lead to a rapid energy release, as demonstrated in this incident.
The case study notes that process industries such as refineries, gas processing units and petrochemical plants are equally at risk from dust explosions, especially in catalyst handling units, coke handling systems, and sulphur recovery units.
Safety recommendations
include installation of dust suppression and extraction systems, explosion-proof electrical equipment, regular dust hazard analysis, proper grounding, and strict housekeeping and inspection protocols.
'The Sigachi Industries incident serves as a stark reminder of the catastrophic potential of dust explosions and the critical importance of robust process safety systems,' the report concludes, urging proactive hazard identification across industrial facilities.
The incident has prompted renewed scrutiny of
process safety standards
across the country's industrial manufacturing sectors.