Silent Killer In Buildings

Ventilation & Smoke Extraction Return Ducts - A Fire Retardant Coating Must.

In almost every major fire disaster, one fact stands out: smoke kills more people than flames. According to NFPA, over 80% of fire fatalities worldwide are due to inhalation of toxic smoke and gases rather than burns. In India, incidents in basements, shopping malls, hospitals, and high-rise offices repeatedly show the same pattern: victims are trapped, visibility drops to zero, and smoke inhalation causes unconsciousness within minutes.

This article focuses on the critical importance of coatings for Ventilation & Smoke Extraction Return Ducts. Too often, designers and builders prioritize the aesthetic appeal of a building while overlooking the life-saving role of Passive Fire Protection, which must be integrated from the very beginning of a project.

The very systems designed to protect us ventilation ducts and smoke extraction return ducts become lifelines during such emergencies. Yet, if these ducts are not fire-resistant, they collapse or even act as channels spreading smoke faster to other floors. This silent design flaw turns buildings into death traps.

As we aspire to create state-of-the-art, smart, and sustainable buildings, safety cannot be an afterthought. Designers, engineers, and facility managers must give utmost importance to fire safety because a fire without smoke is survivable, but a fire with uncontrolled smoke is a massacre.

Lessons from Real-Life Case Studies

Carlton Towers Fire, Bangalore (2010)

A fire broke out in the 12-storey Carlton Towers. While flames were largely contained to certain floors, smoke spread rapidly through ducts and shafts. Most victims died due to asphyxiation. The tragedy shocked Bengaluru and raised questions on smoke control, but little changed in duct fire protection practices.

Grenfell Tower, London (2017)

The fire that claimed 72 lives revealed how smoke moved swiftly through ventilation and service shafts, cutting off escape routes. Survivors described stairwells filled with thick black smoke, underscoring that smoke management and duct integrity are as important as controlling flames.

Indian Hospital Basement Fires (Multiple Cities)

Recent hospital fires in Ahmedabad, Rajkot, and Mumbai all had one thing in common: ventilation ducts acted as smoke highways, carrying lethal gases to patient wards. Most victims were patients who could not be evacuated in time. A fire-resistant duct coating could have bought precious minutes.

Uphaar Cinema Fire, New Delhi (1997)

One of India’s deadliest fire tragedies, claiming 59 lives, was caused not by flames but by suffocation. Thick smoke from a fire in the parking area entered the cinema hall through the ventilation system, leaving audiences trapped. The Uphaar fire showed how unprotected ducts and poor smoke extraction design can turn a public space into a gas chamber.

Why Fire Retardant Coatings Are Essential

Routine Inspections and Maintenance – The Forgotten Link Even the best fire-resistant duct coating will lose effectiveness if not maintained properly. Dust, moisture, mechanical damage, or simple aging can compromise the coating. Unfortunately, most facilities stop caring once the installation is complete, which is a dangerous mistake.

• Inspection Frequency: Duct systems and coatings should be visually inspected at least once every 6 months as part of the building’s fire safety audit.
• Detailed Testing: Every 3–5 years, ducts should undergo a thickness check, adhesion test, and re-application where necessary.
• Common Failures to Watch For: Cracks, peeling paint, corrosion spots, and blockages in ducts.
• Documentation: All inspections and maintenance must be logged in a Fire Safety Register so regulators, insurers, and auditors can verify compliance.
• Accountability: Facility managers must assign specific responsibility to trained personnel or service contractors, ensuring duct fire safety is never neglected.

Regular inspections are critical to ensure that fire-retardant coatings on ducts remain effective. Coatings can deteriorate due to dust, moisture, vibration, or age, and if left unchecked, the ducts may fail during a fire. Facility managers should schedule inspections at least every six months, with detailed checks every 3–5 years for coating thickness, adhesion, and corrosion. Any signs of cracks, peeling, or damage must be addressed immediately through re-coating or repair, and all actions should be recorded in a fire safety register. A coating that is not maintained is as unsafe as having no coating at all.

Remember : A coating that is not maintained is as dangerous as having no coating at all.

Integration with HVAC Controls and Smoke Dampers

Fire-resistant coatings on ducts must be complemented with mechanical smoke control measures. In modern buildings, HVAC systems are directly linked to fire alarm panels so that fans can be shut down automatically or switched into smoke-extraction mode during a fire. At the same time, smoke dampers (fire/smoke-rated shutters within ductwork) must activate to contain and control the movement of toxic gases.

This is not just best practice, but a compliance requirement in many codes :

• NBC 2016 (Part IV, Fire & Life Safety) – Requires smoke management systems in high-rise buildings, hospitals, and underground structures, including automatic fan control and smoke dampers.
• IS 655:1963 & IS 16504:2015 (HVAC Ducts & Fire Dampers) – Provide specifications for duct construction and performance of fire/smoke dampers.
• NFPA 92 (Smoke Control Systems) – Details fan control and damper operation during fire events.
• NFPA 90A (Air-Conditioning & Ventilating Systems) – Mandates automatic shutoff of air-handling equipment to prevent smoke spread.
• UL 555S / BS EN 1366-2 – International standards for fire/smoke damper testing and certification.

Why it matters

Prevents the distribution of smoke through interconnected ducts.

Maintains pressurization in escape routes (stairs, lobbies, refuge areas). Reduces property damage by containing smoke within affected zones. Provides critical evacuation time for occupants and safer access for firefighters. Thus, the integration of duct coatings, HVAC shutdown protocols, and certified smoke dampers is a holistic requirement for life safety. Buildings that ignore this integration compromise both compliance and human safety.

Testing & Certification – A Non-Negotiable Requirement

In today’s safety-conscious world, relying on untested or self-claimed products is a serious risk. Every fire-retardant coating, duct lining, or protective material must undergo rigorous testing and third-party certification to prove its performance under real fire conditions.

• Accredited Laboratories : Products must be tested at recognized institutions such as CBRI, UL, FM Global, or equivalent international labs.
• System-Level Testing : It is not enough to test materials in isolation. Full duct assemblies coated and installed must be tested to demonstrate actual fire performance.
• Regulatory Acceptance : Only certified products will be recognized by enforcement agencies, insurance companies, and international consultants.
• Industry Demand : With increasing scrutiny, builders and facility owners now demand certification as proof of quality and compliance.

Without testing and certification, even the best-designed product may fail when it matters most — during an actual fire. When choosing a fire-retardant duct coating, engineers and facility managers must go beyond marketing claims and verify authentic test certificates. A reliable product will always have a valid report from accredited laboratories such as CBRI, ESL, UL, or FM Global, clearly stating the fire-resistance rating (e.g., 2 hours, 3 hours) and the standard followed (IS, ASTM, BS, or UL).

Importantly, the certificate should confirm that the entire duct system with the coating applied was tested, not just the paint material in isolation. Any product that cannot provide transparent documentation or uses vague wording like “conforms to” without proof should be treated with caution. Insisting on verifiable certification is the only way to ensure performance during a real fire.

Recommendations

A holistic approach is essential ducts should be protected not only against fire but also corrosion, carbonation, and microbial growth, ensuring reliability in both emergencies and daily operation.

Ventilation and smoke extraction ducts are the hidden lifelines of a building. If left unprotected, they can turn into death traps during a fire. Fire-resistant coatings, backed by testing, certification, and strict accountability, are not an expense but an investment in saving lives.

As a practical step, stakeholders may consider trusted suppliers such as www.ameetuff.co.in a favored paint company that has already supplied fire-resistant and fire-retardant coatings for landmark projects including the New Indian Parliament, J&K Tunnels, airports, and other critical infrastructure. Proven performance in such high-profile applications demonstrates the importance of selecting the right partner for passive fire protection.

About the Author

KP Dominic has spent over three decades advocating fire and electrical safety in India’s built environment. He co-founded FSAI, FOCUS, and NFE, and is actively involved in drafting the NBC 2025 (Part IV – Fire & Life Safety). He has delivered hundreds of conferences, seminars, and publications on passive fire protection, electrical safety, and resilient design.

This article is based on the author’s professional experience and serves as a recommendation for safety improvement.