Sigachi factory blast: No fire NOC, sensors didn't work - Probe finds 10 glaring lapses

Forensic and environmental agencies have found that the immediate trigger was the thermal decomposition of MCC — a material that ignites at temperatures above 399°C. Investigators believe this led to a dust explosion, powerful enough to destroy parts of the factory and trap workers. TOI cited the Telangana Forensic Science Laboratory as saying that the overheating of the substance likely caused the explosion, though forensic collection was initially limited due to ongoing rescue efforts.

3. Expired fire safety clearance

At the time of the explosion, Sigachi Industries was operating without a valid Fire No Objection Certificate (NOC). This was confirmed by the District Fire Officer to CNN-News18. The factory’s expired fire clearance highlights yet another serious lapse in regulatory compliance, raising pressing questions about how operations were allowed to continue despite the absence of mandatory fire safety authorisation. The lack of a valid NOC not only violates legal norms but also suggests gaps in routine fire inspections and enforcement mechanisms.

4. Malfunctioning interlocking system

Sources in Telangana’s department of factories have reportedly indicated that the interlocking system, which is designed to automatically cut off heat or sound an alarm when temperatures cross a safe threshold, appears to have failed. This allowed temperatures to rise unchecked, building up heat and pressure. The Indian Express cited officials as stating that maintaining a controlled temperature is critical not just for safety but also to ensure product quality.

5. Choked spray dryer and poor maintenance

According to a Telangana State Pollution Control Board (TSPCB) official quoted by TOI, the blast was likely triggered by a choking in the spray dryer, causing a dangerous build-up of heat and pressure. The official said maintenance at the facility was clearly inadequate. These dryers, if not cleaned and serviced regularly, can become high-risk equipment - a view echoed by former Indian Institute of Chemical Technology chief scientist K Babu Rao, who called poorly maintained spray dryers “ticking time bombs”.

6. Ignored warnings about ageing machinery

As per The Indian Express, an FIR filed by Rajanala Sai Yashwant, whose father was killed in the blast, alleges that workers had repeatedly raised concerns about the ageing machinery at the factory. According to the complaint, the management ignored calls to replace outdated equipment and continued using it despite clear risks. The FIR claims the tragedy was a direct result of this negligence. The case has been registered under charges of culpable homicide not amounting to murder.

7. Unsafe shift timing and worker density

The timing of the blast also contributed to the high death toll. The explosion occurred during shift roll call, when both night and day shift workers were gathered in the dryer area — the most dangerous part of the plant. Powder packing was underway at the time, making the space even more congested, TOI reported.

8. Possible instrumentation and filter failures

Investigators are examining whether there was a malfunction in the sieves or filters that process the powder form of MCC. These components are crucial in maintaining consistency and preventing dust build-up, which can turn explosive under the right conditions. The Indian Express cited a source as indicating that there could have been an instrumentation error, contributing further to the disaster.

9. Regulatory oversight failures

Regulators themselves have raised questions about inadequate inspection and oversight. A TSPCB official told TOI that spray dryers fall under pressure vessel regulation and safety protocols must be strictly enforced by inspectors. He added that the incident was not routine and that the entire inspection system needs re-evaluation. The PCB’s member-secretary G. Ravi confirmed that while the plant had permission to operate until 2027, the board will now issue a closure notice citing suspected violations.

10. Absence of company leadership post-blast

Even days after the tragedy, no senior member of the company’s leadership had visited the site. Telangana Industries Minister D Sridhar Babu criticised the company’s silence, saying that the top leadership must come forward and face the consequences.

Sigachi Industries, incorporated in 1989, describes itself as a global leader in microcrystalline cellulose production. The company, which serves pharmaceutical, food, cosmetic and chemical industries, operates multiple plants in India and exports to over 65 countries. Its corporate office is in Sangareddy, Telangana.