Hyderabad, July 3: The deadly blast at a pharmaceutical facility in Telangana’s Pashamylaram industrial area that killed dozens may have been caused by a dust explosion, not a pressure-related reactor failure as initially suspected, according to forensic experts and scientists.
The explosion occurred on Monday (July 1) at Sigachi Industries, which manufactures microcrystalline cellulose (MCC) powder—a fine material widely used in pharmaceutical production as a binder and filler.
While the Factories Department initially suggested the incident was a Boiling Liquid Expanding Vapour Explosion (BLEVE)—a term used when a pressurised vessel containing liquid overheats and bursts—experts say evidence at the blast site suggests otherwise.
“This was a dust explosion,” said fire forensics specialist Zuber Ali Khan, citing tell-tale signs such as the positive and negative wavefronts, fragment impact, ground shock, and dynamic drag loads observed at the site. “The outward and inward blast patterns are consistent with a dust-induced event.”
K. Babu Rao, a retired scientist and industrial safety expert, also concluded the blast was a dust explosion. He estimated the energy release to be equivalent to a 400 kg TNT detonation. According to Rao, the MCC production process—especially the spray-drying phase, where hot air turns MCC slurry into powder—creates a volatile environment if dust microns accumulate in confined spaces.
“The ignition temperature for such dust is just 232°C, and any breach in control could lead to a catastrophic blast,” he explained. The incident has renewed scrutiny of industrial safety enforcement in Telangana. Experts have accused the Factories Department of regulatory failure, alleging irregular inspections and leniency toward companies involved in past accidents.
“They don’t carry out regular checks. After accidents, they protect companies by issuing favourable reports,” Rao said. He noted that a 2024 reactor blast at SB Organics in Sangareddy district remains uninvestigated, with no report published over a year later.
Criticism also mounted over the department’s response to another pharma blast last year, which was attributed to static electricity, with workers blamed for not wearing safety gear while the company was cleared of responsibility. The latest incident has reignited calls for tighter oversight of industrial safety protocols, particularly in high-risk sectors such as pharmaceuticals.
