A Malaysian home kitchen with an extractor hood above the hob

Kitchen Smoke: The Haze You Make Indoors

By Boey Tze Zhouon Sep 25 2026Updated on Oct 06 2026

Kitchen smoke is indoor air pollution you make yourself, and in a Malaysian home it can be the largest source you actually control on a day when the outdoor air is fine. High heat frying puts particles into the room you are standing in. The fix is ventilation that reaches outside, not a filter that recycles the same air.

We are ORGANO, and TYGRON® is our tiger milk mushroom (Lignosus rhinocerus) functional food, formulated in Australia and made in Malaysia by Fungitech Sdn Bhd. Every haze season people talk about what comes in through the window. Almost nobody talks about the wok, which runs twice a day, all year.

Does cooking really pollute the air in your house?

Yes. The United States Environmental Protection Agency, updated March 2026, lists cooking first among the ways particles are generated indoors, and notes that "Burning food during cooking quickly produces large quantities of indoor PM."

The Washington State Department of Health, in a document published in April 2024, adds that the stove type is not the escape hatch: "Cooking on all stove types produces fine particulate matter (PM2.5), which is a mixture of particles that can be inhaled deep into the lungs." Induction and electric hobs make fewer combustion gases, but the food and the oil still make particles.

How much smoke does a wok actually make?

More than most people would guess, and the honest answer is a range. In a California Air Resources Board study published in 2001, kitchen PM10 ranged from 60 to 1,400 micrograms per cubic metre during cooking on a gas stove. That study measured PM10, not PM2.5, in a single test home, so read it as scale rather than a Malaysian figure.

A 2022 study in Environmental Science and Ecotechnology did something more useful for a cook: it measured at eleven heights in one Beijing kitchen across 18 cooking sessions, and its finding is oddly practical. "Intense cooking, e.g., stir-frying, pan-frying, or cooking on high heat, tended to shoot PMs to the upper layers, while moderate ones left PMs within the breathing zone." The authors are candid about the limit: "However, it should be noted that the measurements were only conducted in one kitchen."

For scale, the World Health Organization's 2021 air quality guidelines set PM2.5 at 5 micrograms per cubic metre annually and 15 over 24 hours, and state that "The present guidelines are applicable to both outdoor and indoor environments globally." A ten minute peak is not a 24 hour average, so the comparison is directional.

Steam and smoke rising from a wok on a high flame in a Malaysian home kitchen — High heat is what makes the smoke. The extractor is what decides where it goes.

Is cooking smoke linked to cancer?

There is a formal classification, and it is narrower than the headlines suggest. In 2010 the International Agency for Research on Cancer, part of the World Health Organization, evaluated the evidence and concluded: "Emissions from high-temperature frying are probably carcinogenic to humans (Group 2A)."

Three things it does not say. It is about the emissions, not about fried food. Group 2A describes hazard, not how large the risk is, so it cannot become a percentage or a comparison to smoking. And the agency recorded the weakness of the evidence itself: "There is limited evidence in humans for the carcinogenicity of emissions from high-temperature frying." It also found that "No differences were apparent between stir-frying, deep-frying and pan-frying when these methods were investigated separately".

Do the global household air pollution figures describe your kitchen?

This is the part most articles get wrong, and it cuts against a scarier story. The World Health Organization's household air pollution fact sheet, updated in December 2025, carries very large death and illness figures. Those describe cooking on solid fuels and kerosene over open fires, mostly in rural low and middle income households, and it notes that in 2021 only 14 percent of urban populations relied on polluting fuels, against 49 percent of the global rural population.

A Malaysian home cooking on bottled gas is not that population, so borrowing those numbers here would be dishonest. What travels is the mechanism, not the burden.

Does your kitchen hood actually work?

It depends on one thing: whether it sends the air outside. The Washington State Department of Health is direct. "Recirculating hoods are generally much less effective than ducted hoods in removing pollution from cooking", and "A fan that exhausts to the outside is critically important to control cooking pollution."

That matters more here than most places, because the charcoal filter hood with no duct is the default in condominiums and many terrace kitchens, simply because there is nowhere to run a duct. If yours does not vent outside, it captures grease and odour and little of the particle load.

Even ducted hoods vary enormously. In laboratory testing by Lawrence Berkeley National Laboratory researchers, published in Environmental Science and Technology in 2012, capture efficiency across seven ducted hoods ranged from under 15 percent to over 98 percent, varying with airflow and with which burner was used. Back burners were captured far better than front ones. The tests used burner gases, not cooking smoke, so the figures describe the hood rather than your dinner.

What changes the most, for the least money?

In rough order of return, none needing a renovation.

Use the back burner. The free change with the clearest mechanism behind it: airflow to the hood is better and less of the plume escapes.
Turn the extractor on before you start and, in the Environmental Protection Agency's words, "Leave it on for 10-20 minutes after you are done cooking." Particles do not stop when the flame does.
Open a window across the kitchen when the outdoor air is good, so the extractor has replacement air. On a hazy day, close it.
Drop the heat where the dish allows. The classification above is specifically about high temperature frying.
Do not char food indoors. Burning food makes particles fast.
Clean the hood filter. A grease clogged mesh moves less air, and captures less.

On a haze day the two problems collide: you want the windows shut and the kitchen ventilated. Cook simpler food that day, run the extractor anyway, and keep the kitchen door closed. Our guide to indoor air quality during haze covers the rest of the house, and what size air purifier you need covers the machine.

The exposure that runs all year

Kitchen smoke is a year round exposure nobody counts, which makes it the opposite of haze: less dramatic, more constant. If a cough lingers long after the sky clears, that has its own explanation, and the kitchen is worth checking too. Because this exposure is daily rather than seasonal, the habit that matches it is also a daily one. The national Malaysian Herbal Monograph records folk use of Lignosus species for coughs and colds, filed as traditional use rather than clinically proven use. After 20 years of mushroom learning and cultivation, the honest version from our household is that tiger milk mushroom belongs in the morning routine.

Every morning

TYGRON® 1 Box

An 8-in-1 blend built around tiger milk mushroom sclerotium, in an elderberry flavour children will actually finish. Adults 1 to 2 sachets a day, ages 7 to 18 one sachet, ages 2 to 6 half a sachet. Not suitable under 2.

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Frequently asked questions

Is cooking smoke bad for you?

Cooking produces fine particulate matter on every stove type, and fine particles are respiratory irritants. The International Agency for Research on Cancer classifies emissions from high temperature frying as probably carcinogenic to humans, Group 2A, while stating that the human evidence is limited. That is a reason to ventilate properly, not to stop cooking: a hood that vents outside, the back burner, and lower heat where the dish allows.

Is a ductless kitchen hood any good?

For grease and odour, yes. For particles, much less. The Washington State Department of Health states that recirculating hoods are generally much less effective than ducted hoods at removing cooking pollution, because they return the same air to the room. If your kitchen cannot take a duct, compensate with an open window when the outdoor air is good, lower heat, and a closed door.

Should I still cook with the windows closed during haze?

Yes, keep them closed, but run the extractor anyway and cook something that makes less smoke that day. You are choosing between two sources rather than eliminating one. Boiling, steaming and simmering produce far less than high heat frying, and a closed kitchen door keeps what you do make in one room.

Does an air purifier remove cooking smoke?

It helps afterwards, and it is not a substitute for the extractor. A purifier removes particles already in the room; an extractor stops them entering it, and removal at source is the stronger control. In an open plan kitchen, expect a purifier to shorten how long the smell lingers rather than stop the peak.

About TYGRON®

TYGRON® by ORGANO is a tiger milk mushroom functional food taken daily by families in Malaysia and Singapore. It holds the Malaysia Book of Records for the highest 1,3/1,6 beta-glucan content in tiger milk mushroom in Malaysia. 1,3/1,6 beta-glucan is the most important active compound and quality benchmark in tiger milk mushroom, and a higher content signals greater potency and quality.

TYGRON® is formulated in Australia, designed by our Sydney-based team (Fungitech Australia Pty Ltd) to one of the world's most stringent functional-food standards, then manufactured in Malaysia under GMP, HACCP and Halal-certified conditions. Why TYGRON® is formulated in Australia.

About the author

This article was written and reviewed by Boey Tze Zhou, Founder and CEO of ORGANO. Boey holds a Bachelor of Agricultural Science (First Class Honours) from Universiti Putra Malaysia and has completed Stanford University's Introduction to Food and Health and the University of Minnesota's Integrative Health and Medicine specialization (including Herbal Medicine) through Coursera. Across 20 years of mushroom learning and cultivation, he developed the TMM365+ slow-grown method behind the Malaysia Book of Records beta-glucan certification held by Fungitech Sdn Bhd. He is an international speaker on functional mushrooms, invited to China International Mushroom Day 2025 and other mushroom-science events across the Asia-Pacific, and was named one of the Top Ten Outstanding Penang Youth (TOPY) in 2024. Read more about the founder

Sources

This article is general information, not medical advice. TYGRON® is a functional food. If symptoms are severe or persistent, please see a doctor. TYGRON® and the ORGANO logo are registered trademarks of Fungitech Sdn Bhd, registered in Malaysia.

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