Do Sprinklers Make Fire Worse? – Myth vs Fact

In US fires large enough to set them off, sprinklers operated and controlled the fire in 88% of cases. Properties with sprinklers also had an 87% lower death rate per 1,000 reported fires than properties with no automatic extinguishing system.

(Source: NFPA, U.S. Experience with Sprinklers, July 2017, covering 2010 to 2014. These are US figures; India does not collect this data.)

The myths

We hear these all the time from society committees, shop owners and even builders:

• “Sprinklers spread the fire.”
• “Sprinklers will flood the whole flat.”
• “Only big buildings need sprinklers.”

These beliefs are wrong, and they are dangerous. They delay installation, and they lead people to switch off or cover sprinklers that are already there.

The facts

Sprinklers do not all go off at once like in the films. In a standard system, only the heads heated by the fire open, and they spray water on the fire below them, not on the whole floor. NFPA found that in 88% of US home fires where sprinklers operated, just one head opened.

Each head is held shut by a small glass bulb filled with liquid. When the air around it gets hot enough, the liquid expands and the bulb breaks. The most common red bulbs break at about 68°C; bulbs of other colours are rated for higher or lower temperatures. Cigarette smoke or steam from cooking will not set them off.

Far from making a fire worse, sprinklers cool the fire and the room, stop the fire from growing and cut down the smoke that kills most people in building fires. They start working while people are still escaping, long before the fire brigade arrives.

What the records show

Measure	Figure	Source
Fire accidents in India, 2024	5,971 cases; 5,888 deaths	NCRB ADSI 2024
Share of those deaths in residential buildings	60.4% (3,555 deaths)	NCRB ADSI 2024
US reported fires with sprinklers present, 2010 to 2014	10%	NFPA, 2017
US: sprinklers operated, in fires large enough to set them off	92%	NFPA, 2017
US: sprinklers operated and controlled the fire	88%	NFPA, 2017
US: death rate per 1,000 fires, sprinklered vs no system	87% lower	NFPA, 2017

NCRB does not record whether a building had sprinklers, so there is no reliable Indian figure for deaths in sprinklered versus unsprinklered buildings. Country-by-country sprinkler coverage figures are not shown because we found no reliable source for them.

Myth or fact?

Myth	Fact
“All the sprinklers go off during any fire.”	Each head opens only when the fire heats it. The rest stay shut.
“The water causes more damage than the fire.”	In 88% of US home fires where sprinklers operated, only one head opened, which limits the water used. A small, controlled fire with some water damage is far better than a burnt-out home.
“I will just use extinguishers.”	Portable extinguishers are meant for small fires in their early stage. Sprinklers keep working while people escape, even at night when everyone is asleep.
“Only big buildings need sprinklers.”	Fires kill people in homes of every size. Building rules decide where sprinklers are required, but any building where people sleep or gather benefits from them.
“Installing sprinklers is too expensive.”	Cost depends on the building. Ask a qualified fire engineer for a quote and weigh it against the lives and property at stake.

What you can do today

• Check whether your home, office or shop has sprinkler heads.
• Ask your society or builder for the latest fire system test report, and ask whether the sprinkler pump and valves are kept switched on.
• Never cover, paint or hang anything from a sprinkler head. A painted head may not open.
• Do not stack goods right up to the ceiling. Sprinklers need clear space below them to spray.
• Support stronger sprinkler rules for buildings where people sleep or gather, such as hospitals, hostels, hotels and high-rises, and their proper enforcement.
• Share this article with your society committee or school management.

Ask your builder one question

“When was our sprinkler system last tested?” If nobody knows, insist on a test by a qualified agency. A sprinkler system that is switched off or never maintained gives a false sense of safety.

References

• NFPA, U.S. Experience with Sprinklers (Marty Ahrens, July 2017)
• NCRB, Accidental Deaths & Suicides in India 2024, Chapter 1
• BIS IS 15105:2021, Design and Installation of Fixed Automatic Sprinkler Fire Extinguishing Systems, Code of Practice
• BIS, Learning Science via Standards: Fire Extinguisher