Indian Cooking Indoor Air Pollution

The Source Hiding in Plain Sight

Indian conversation about air pollution is almost entirely about outdoor air — stubble
burning, traffic, construction, the winter AQI. All of it real. But it leaves out something
that happens in every home, twice a day, a few feet from where people are standing.

Cooking is a significant source of indoor fine particulate. This is well established in the
research literature and almost entirely absent from consumer conversation — partly because it
is uncomfortable, and partly because no brand has an obvious interest in raising it.

It deserves saying clearly: this is not an argument against Indian cooking.
It is an argument for the extractor fan above it, and for understanding when your indoor air is
worst — which, on many days, is not when the outdoor AQI is highest.

What Happens When You Cook

Three separate processes generate particulate, and most Indian cooking runs all three at
once.

Oil aerosolisation

Heat oil sufficiently and it does not merely get hot — it releases fine droplets and
breakdown products into the air. The hotter the oil and the longer it is held there, the more
is released. Deep-frying and tempering are the clearest examples.

Thermal breakdown of food

Browning, charring and roasting break organic material down into volatile compounds and fine
particles. This is the same chemistry that produces the aromas — the smell of food cooking
is airborne material reaching you.

Combustion from the burner

An LPG flame is combustion occurring inside your kitchen. It produces nitrogen dioxide and
ultrafine particulate independently of the food, and it does so the entire time the hob is
lit.

Which Techniques Spike Air the Most

Technique	Why it emits	Relative impact
Tadka / chhaunk	Oil taken to very high heat, spices added — rapid aerosolisation	Sharp, intense spike
Deep-frying (puri, pakora, samosa)	Large volume of oil, sustained high temperature	Highest sustained
Roti on open flame	Direct charring plus the burner’s own combustion	High, repeated per roti
Dry-roasting spices	Thermal breakdown without oil	Moderate, brief
Tawa shallow-frying	Moderate oil, moderate heat, long duration	Moderate but prolonged
Pressure cooking / boiling	Steam, minimal aerosol; burner emissions only	Low

The pattern is consistent: heat plus oil plus open air is what emits. A
covered pressure cooker is a quiet appliance in air-quality terms. An open kadhai at frying
temperature is not.

The Gas Flame Itself

Separate from what you are cooking, the burner is its own source. Gas combustion in an
unvented indoor space produces nitrogen dioxide and ultrafine particles, and in a small kitchen
with the door closed and no extraction, these accumulate for as long as the flame is lit.

This is the strongest air-quality argument for induction, and it is worth stating precisely:
induction removes the burner’s emissions entirely. It does not reduce the particulate
produced by the food itself — hot oil aerosolises the same way on an induction hob. Switching
helps; it does not solve.

How Long It Lingers

Visible smoke clears quickly and is misleading. Fine particulate — the fraction small enough
to reach deep into the lungs — stays airborne far longer, and in a kitchen without effective
extraction can remain elevated for an hour or more after the hob is off.

Two practical consequences follow, and they are the most actionable things in this
article:

• Turn the extractor on before you start, not when smoke appears. By the
  time you can see it, dispersal has already begun.
• Leave it running for 10–15 minutes after you finish. Switching it off
  with the hob leaves the longest-lived fraction in the room.

There is also a layout consideration. Open-plan kitchens — increasingly common in Indian
apartments — remove the wall that used to contain cooking emissions. The living room now shares
the kitchen’s air, which makes source extraction considerably more important than it was in a
closed kitchen.

What Actually Reduces It

1. A properly sized chimney, used every time. Extraction at source beats
   filtration after dispersal, decisively. The most common failures are a chimney too small for
   the hob, ducting that is too long or too convoluted, and — most often — simply not switching
   it on for “quick” cooking.
2. Clean the chimney filters. A grease-clogged baffle drastically reduces
   extraction. This is the chimney equivalent of never changing a water filter.
3. Cross-ventilate while cooking, when outdoor air permits it. On a severe
   AQI day this trade becomes genuinely difficult, and extraction plus a closed kitchen door is
   the better option.
4. Close the kitchen door if you have one, to contain emissions rather than
   letting them reach bedrooms.
5. Filter what escapes. An air purifier in an adjoining living area handles
   the fraction that got past the chimney. In an open-plan home this is the realistic use case —
   but it is second to extraction, not a substitute for it.

A Word Against Panic

It would be easy to read this as an argument that Indian cooking is dangerous. It is not,
and we would rather not join the long tradition of brands selling appliances through fear.

People have cooked this way for a very long time. What has changed is the context: kitchens
are smaller and better sealed, open-plan layouts share kitchen air with living space, ambient
outdoor levels are already elevated, and more homes are cooking with the windows shut for more
of the year.

The reasonable response is not to change how you cook. It is to extract properly, ventilate
when the outdoor air allows, and know that the hour after dinner is when your indoor air is at
its worst — which is useful information whether or not you ever buy an appliance for it.

Frequently Asked Questions

Does Indian cooking cause indoor air pollution?

Yes, and substantially. High-heat techniques central to Indian cooking — tempering spices in hot oil, deep-frying, dry-roasting, and cooking roti directly on a flame — aerosolise oil and organic material into fine particulate. Indoor PM2.5 during and after cooking commonly rises well above the level in the same kitchen an hour later.

Is a kitchen chimney better than an air purifier for cooking smoke?

For cooking specifically, yes — and it is not close. A chimney captures at the source, before particles disperse into the room. An air purifier can only filter what has already spread. They are complementary rather than alternatives: extract at the hob, filter what escapes.

Does tadka cause air pollution indoors?

Tempering spices in hot oil is one of the sharper particulate events in a home kitchen. Oil is taken to a high temperature and spices are added, aerosolising oil droplets and organic compounds within seconds. The spike is brief and pronounced — which is exactly why running the extractor before you start matters more than switching it on afterwards.

Is a gas stove worse than induction for indoor air?

For air quality, yes. A gas flame is combustion happening in your kitchen, producing nitrogen dioxide and fine particulate in addition to whatever the food produces. Induction heats the pan without combustion, so it eliminates the burner’s own emissions — though it does not reduce the particulate from the cooking itself.

How long does cooking smoke stay in the air?

Longer than people expect. Visible smoke clears in minutes, but fine particulate can remain elevated for an hour or more in a poorly ventilated kitchen. The practical implication is that the extractor should keep running well after cooking ends, not be switched off with the hob.