Brussels, Belgium – Cooking on gas regularly fills kitchens with air pollution above recommended levels, the largest-ever home monitoring study in Europe has found.

The World Health Organization (WHO) daily limit value for nitrogen dioxide (NO₂) exposure was broken in most (57.3%) of the homes using gas hobs and/or gas ovens that were tested under normal living conditions by leading scientific researchers.

NO₂ levels were found to be almost twice as high in kitchens, living rooms, and bedrooms in homes cooking on gas compared to those using electric appliances, on average. Breaches in 15.9% of homes using electric appliances were caused mainly by outside air pollution blowing in, the researchers say.

The research, commissioned by nonprofit energy efficiency group CLASP, was conducted by the Netherlands Organisation for Applied Scientific Research (TNO). Sensors were placed in 247 homes [1] in seven countries with large populations cooking on gas and childhood asthma cases linked to cooking on gas.

Breaching limit values increases health risks. NO₂ can cause inflammation of human airways, coughing and wheezing, reduced lung function, and increased asthma attacks, especially in children. Children in homes with a gas cooking appliance have a 20% increased risk of suffering a lower respiratory illness, the WHO estimates.

Pollution spikes in homes cooking on gas could last several hours and were more intense the longer the cooking time, the researchers found. Added together, the WHO daily limit was breached for 3.25 days over the 13-day testing period, on average. Where kitchens had fans to extract fumes outdoors, they did not clear much pollution. This is because of improper use, the researchers think.

Extrapolating to a year, the data shows that a quarter of homes (25%) cooking on gas breached EU and UK hourly NO₂ limits for outside air quality. Authorities across Europe have been forced to respond to breaches of these limits. Yet EU regulators have not set limits for indoor air pollution.

Little has been done to prevent NO₂ pollution from gas cooking appliances in Europe, CLASP wrote in its report summarizing the research. Various regulations could limit air pollution from appliances, but fail to, it said. The problem could be corrected at EU level next year when new design and labelling rules are expected to be adopted.

At a stakeholder meeting with EU officials, initially set for 30 November 2023 and postponed until March 2024, CLASP will call for a new EU energy label comparing gas and electric hob efficiency and highlighting pollution levels.

Nearly a third (32.5%) of homes in the EU cook on gas. But few are aware of the risks due to the invisible nature of the pollution, according to a recent opinion poll commissioned by CLASP and conducted by Opinium. If made aware, up to three quarters of respondents (74%) say they would consider getting rid of their gas appliances.

Nicole Kearney, CLASP Europe Director, said: “Our research reveals the severity of air pollution caused by gas cooking appliances in homes across Europe. Cooking up a change starts with awareness. Empowering people with knowledge on the health risks of these products is essential, and they need resources to upgrade to cleaner and healthier hobs and ovens. In turn, governments must protect public health, tackling air pollution at the source and supporting the transition to cleaner cooking.”

TNO senior scientist, Piet Jacobs, said: “Based on our field study data we estimate that in about 25% of the European kitchens cooking on gas the EU NO₂ limit value for 1-hour exposure is exceeded, where outside levels were below these values. Changing to electric cooking, preferably combined with use of well-designed ventilation hoods to reduce exposure to high levels of particulate matter from cooking, can bring these values down to below recommended levels.”

Professor Frank Kelly of Imperial College London said: “Gas hobs and ovens are a major source of indoor air pollution, including NO₂, which can both exacerbate existing health conditions and potentially lead to new respiratory illnesses. For children with asthma, the presence of gas cooking appliances can intensify their symptoms. Removing these appliances from our homes will improve indoor air quality and mitigate potential risks to public health.”

The scientists also measured for fine particulate matter. In kitchens, this is caused by outdoor pollution blowing in and food cooking, rather than the appliance fuel source. The scientists found no significant difference in emissions between homes cooking on gas and electric.

Ends

CLASP Report – Clearing the Air: Gas Cooking and Pollution in European Homes

TNO Report – Health Effects in Europe from Cooking on Gas – Phase II Field Study

Press releases are available in the following languages:

Dutch, English (UK), English (US), French, German, Hungarian, Italian, Romanian, Slovak, Spanish.

Contacts

• CLASP Europe director Nicole Kearney (EN) +44 75 4486 5924
• CLASP Europe senior communications associate Païline Caroni (EN, FR) +32 473 127 674.
• ICL professor Frank Kelly (EN) +44 (0)20 7594 8098
• CLASP communications consultant Jack Hunter (EN) +33 751 051 805
• TNO press officer Maarten Lörtzer (EN, NL) +31 620420732.

About CLASP:

CLASP is an international nonprofit leading the research and promotion of appliance efficiency and energy access to improve the lives of people and the planet. CLASP works to combat climate change and drive the transition to a more energy-efficient and just future where no one is left behind. Headquartered in Washington DC, and based in Beijing, Brussels, Dehli, Jakarta and Nairobi, CLASP works with governments, appliance manufacturers and partners to advance positive change on a global scale.

 

Notes

[1] Market research firm Opinium selected 40 homes each in France, Italy, the Netherlands, Romania, Slovakia, Spain, and the UK, where residents cook at least 3 days a week, are non-smokers, and are not near busy main roads or industrial plants. More than 40% of homes include children. One in 5 cook purely on electric, while 4 in 5 cook purely on gas, either ovens, hobs or both. In all homes, sensors were placed in the kitchen, living room and a bedroom to measure NO₂, fine particulate matter, and carbon monoxide. Outdoor sensors detected NO₂. Participants were told to cook and behave normally. Each was paid €100. Only data from 247 homes that successfully followed instructions over a 13-day period in 2023 were included. The previous largest EU study of exposure to NO₂ based on continuous sensor data took readings from 16 homes.

In collaboration with the Netherlands Organisation for Applied Scientific Research (TNO) and Opinium Research, CLASP conducted a study across seven European countries in 2023 to assess the impact of gas cooking on indoor air quality. The research involved monitoring in-home air quality in gas- and electric-cooking households, collecting household and cooking behaviour data, and analysing indoor pollutant concentration levels.

The report tackles several critical questions:

• What are the levels of indoor air pollution in households with gas cooking appliances and how do they compare to households that cook with electric appliances?
• How do these pollution levels compare to established mandatory outdoor air quality standards as well as pollution levels recommended by the WHO?
• Is ventilation enough to mitigate the health risks linked with gas cooking, or is a transition to cleaner cooking technologies necessary?

The report’s key findings provide a compelling call to action:

• Gas cooking often results in indoor air pollution that exceeds WHO air quality limits, putting citizens at risk of severe health issues.
• Many households with gas cooking appliances exceed WHO air quality guidelines for nitrogen dioxide (NO₂).
• Electric-cooking households, in contrast, enjoy significantly better indoor air quality, free from NO₂ pollution caused by kitchen appliances.
• Ventilation alone is insufficient to mitigate the pollution, necessitating a transition to cleaner electric cooking.

To safeguard public health, it’s essential to educate people about the health risks associated with gas appliances and provide them with resources to transition to cleaner and healthier cooking technologies. CLASP calls for collaborative efforts from governments, industry, civil society, healthcare providers, and individuals to improve indoor air quality across Europe.

Additional Resources

TNO Report: Health Effects in Europe from Cooking on Gas – Phase II Field Study

Executive Summary Translations

Dutch, French, German, Hungarian, Italian, Romanian, Slovak, Spanish

Press Releases

Dutch, English, French, German, Hungarian, Italian, Romanian, Slovak, Spanish.

Report Figures Available for Download

Figure 1. Gas cooking appliances directly emit harmful pollutants, whereas PM_2.5 is emitted by the process of cooking food

Figure 2. Criteria for household monitoring selection

Figure 5. Comparison of average NO₂ concentrations in gas- and electric-cooking homes

Figure 6. Average NO₂ concentrations per country and per cooking method in different rooms

Figure 9. Average exceedance of WHO and EU/UK NO₂ limit values in gas- and electric-cooking homes

Figure 10. Average number of exceedance days of the WHO daily guideline value during the 13-day measurement period

Figure 11. Highest hourly CO concentrations found in the kitchen, per country and per cooking method

Figure 12. Average PM_2.5 concentrations in the kitchen, per country and per cooking technology

Figure 14. Overview of ventilation types recorded in the study

Figure 15. Comparison of average indoor-attributed NO₂ concentration throughout the home, by cooker type

Figure 16. Average PM_2.5 concentration in kitchen for all homes cooking on gas and electric hobs

Figure 17. Reasons for using ventilation in the kitchen: results from a 2023 CLASP consumer survey

Figure 18. Average NO₂ concentrations in the Netherlands in the kitchen, living room, bedroom, and outdoors

Figure 19. Map of gas- and electric-cooking households in the Netherlands showing NO₂ levels

Figure 21. Average NO₂ concentrations in Italy in the kitchen, living room, bedroom, and outdoors

Figure 22. Map of gas- and electric-cooking households in Italy, based on severity of NO₂ levels

Figure 24. Average NO₂ concentrations in Spain in the kitchen, living room, bedroom, and outdoors

Figure 25. Map of gas- and electric-cooking households in Spain, based on NO₂ levels

Figure 27. Average NO₂ concentrations in France in the kitchen, living room, bedroom, and outdoors

Figure 28. Map of gas- and electric-cooking households in France, based on severity of NO₂ levels

Figure 30. Average NO₂ concentrations in Slovakia in the kitchen, living room, bedroom, and outdoors

Figure 31. Map of gas- and electric-cooking households in Slovakia, based on severity of NO₂ levels

Figure 33. Average NO₂ concentrations in Romania in the kitchen, living room, bedroom, and outdoors

Figure 34. Average corrected NO₂ concentrations in Romania, taking into account higher levels of outdoor air pollution

Figure 35. Map of gas- and electric-cooking households in Romania, based on severity of NO₂ levels

Figure 37. Average NO₂ concentrations in the United Kingdom in the kitchen, living room, bedroom, and outdoors

Figure 38. Map of gas- and electric-cooking households in the United Kingdom, based on severity of NO₂ levels

Guidance Materials for Participating Households

Field Testing Equipment Overview

Field Testing Equipment Installation Guide

Household Recruitment Questionnaire

Instructional Videos for Participating Households: Dutch, English, Italian, French, Romanian, Slovak, Spanish

 

Visit our Cook Cleaner Europe page to view additional resources on gas and electric cooking.

Despite decades of research establishing links between gas cooking emissions and health impacts, misconceptions about both gas and electric kitchen appliances remain widespread. Many households across Europe are still unaware of the risks associated with gas hobs and ovens. CLASP’s report “European Consumer Perspectives of Gas and Electric Cooking” draws evidence from national surveys conducted across France, Romania, Spain, and the United Kingdom, shedding light on a critical public health concern.

Key findings from the report include:

• A willingness to switch to electric for health reasons: The majority of respondents (ranging from 58% to 74% in different countries) would consider abandoning their gas cookers if they were aware of health issues associated with them. This highlights a significant opportunity to reduce indoor air pollution and protect public health through further awareness-raising activities.
• Safety perceptions: Consumers generally perceive electric cooking as safer than gas despite lacking full awareness of the health risks associated with gas appliances.
• Barriers to switching: Consumers view cost as a significant obstacle to transitioning from gas to electric cooking. Renters face additional challenges, with many reporting an inability to change to electric appliances.
• Public support for government intervention: An overwhelming majority of respondents (ranging from 77% to 88% in different countries) strongly supports government initiatives aimed at promoting electric cooking.
• Energy efficiency concerns: Consumers care about the energy efficiency of their cooking appliances but lack the tools to effectively compare gas and electric options. They strongly support the idea of an energy-efficiency label for hobs and ovens.

Further research and action are needed to overcome the barriers to electrifying cooking in Europe. Facilitating the transition to electric cooking, raising awareness of health risks, and implementing energy-efficiency labels can pave the way for healthier and more sustainable households.

Access the full report

Additional resources on gas and electric cooking in Europe

For media inquiries and more information, please contact

Païline Caroni
Senior Communications Associate (Europe) – CLASP
pcaroni@clasp.ngo

About CLASP:

CLASP is an international nonprofit leading the research and promotion of appliance efficiency and energy access to improve the lives of people and the planet. CLASP works with governments, industry, communities, and others to propel policies and markets toward the highest-quality, lowest resource-intensive products possible.

While decades of scientific research have established a correlation between the emissions from gas cooking appliances and detrimental health impacts, the findings have not been widely circulated amongst the European public. As a result, misconceptions and misinformation about the safety, performance, and efficiency of electric alternatives remain widespread.

This report’s findings are drawn from surveys conducted among nationally representative samples of 3,000 adults in France, Romania, Spain, and 2,000 adults in the United Kingdom (UK). It offers European policymakers valuable insights into consumer perspectives on both gas and electric cooking appliances.

 

CLASP’s research questions address the following:

• Consumer use of and reasons for gas versus electric cooking appliances.
• Awareness of the health risks associated with gas cooking, and practices – such as ventilation – that can reduce risks.
• The importance of energy efficiency in major appliance purchase decisions and the value of a comparative energy label for gas and electric cookers.
• The level of support for government schemes to accelerate the transition to electric cooking.

Key findings of the report include:

• Variations in preference and usage of gas and electric cooking appliances are evident across countries, but also among distinct demographic segments.
• Cost emerges as a significant barrier for consumers, hindering the transition from gas to electric appliances. Renters wanting to switch to electric cooking appliances may face obstacles, despite their preference for such appliances.
• Consumers perceive electric cooking as safer than gas cooking, yet many remain unaware of, or indifferent to, the health risks associated with gas cooking appliances.
• Most respondents (58–74%) said they would consider getting rid of their gas cooker if they knew it was linked with health issues.
• Less than 20% of respondents across all countries indicated using ventilation to mitigate indoor air pollution when cooking.
• There is substantial public support for government initiatives aimed at promoting electric cooking in Europe.
• Consumers express a strong interest in the energy efficiency of their cooking appliances; however, they lack the means to effectively compare different types of hobs. Consumers strongly support the implementation of an energy efficiency label for both hobs and ovens.

While this report provides valuable insights, further research is needed to understand the barriers and opportunities for electrifying cooking across Europe.

Translations of the report’s executive summary are available:

• French: Résumé – Les perspectives des consommateurs européens sur la cuisson au gaz et à l’électricité : Preuves tirées de quatre enquêtes nationales
• Italian: Riepilogo – I punti di vista dei consumatori europei sulla cottura a gas ed elettrica – i risultati di quattro indagini nazionali
• Romanian: Rezumat – Perspective ale consumatorilor europeni în privința gătitului cu gaz și electric: Dovezi din patru sondaje naționale
• Spanish: Resumen – Perspectivas de los consumidores europeos sobre las cocinas eléctricas y de gas: Cuatro encuestas nacionales

Individual survey reports:

• France
• Romania
• Spain
• UK

Visit our Cook Cleaner Europe page to view additional resources on gas and electric cooking.

This press release was originally posted by Global Action Plan.

A new study by CLASP, with technical input by the Netherlands Organisation for Applied Scientific Research (TNO), suggests based on simulations that cooking with gas in a home kitchen without ventilation emits levels of air pollution that exceed World Health Organisation air quality guidelines and outdoor UK air pollution standards. More than half of UK homes cook with gas, equating to over 36 million people in the UK that may be exposed to levels of air pollution that violate UK outdoor regulations. TNO is currently carrying out a field study in the UK to validate the simulation results.

When in use, gas hobs and ovens emit carbon monoxide, carbon dioxide (CO₂), and nitrogen dioxide (NO₂) which can linger indoors for hours after use. Research indicates exposure to high levels of outdoor air pollution can cause strokes, heart disease, lung cancer, and both chronic and acute respiratory diseases, including asthma.

The economic and welfare burden of air pollution is significant. CLASP estimates that indoor air pollution from gas cooking costs the UK around £1.4 billion annually in healthcare costs,  including lower life expectancy, illnesses, greater healthcare expenditure, and lower productivity. There is also growing evidence that links combustion-related air pollution with adverse effects on brain development in young children.

While the health risks of air pollution have been widely explored and publicised, the relationship between cooking on gas and indoor air quality are yet to receive the same level of public awareness.

The study determined that this is a significant but solvable public health and environmental problem, and that the UK Government has a policy opportunity to transition to cleaner alternatives but is failing to act.

Gas cooking undermines UK targets to become a climate-neutral economy by 2050. As a fossil fuel, burning gas when cooking emits both CO₂ and unburned methane, two potent greenhouse gases. With around 54% of UK households cooking on gas, cooking alone accounts for roughly 2% of total UK carbon emissions. Even when switched off, gas hobs leak methane. Methane is the main component of fossil gas used for cooking and when leaked, it can warm the Earth more than 80 times as much as the same amount of CO₂ over a 20-year period.

While boilers sold in the UK have set NO₂ emission limits, and incentives are available to upgrade to more efficient and climate-friendly heat pumps, no such policies exist for cooking appliances.

CLASP and partners are calling for the UK Government to:

• Adopt laws to protect consumers by setting limits on pollution emissions from gas cooking appliances and ensure that hobs and ovens are efficient.
• Provide a new Energy Label to enable people to directly compare the efficiency and emissions of gas and electric cooking appliances.
• Accelerate the transition to cleaner electric cooking by coupling incentives for heating and home upgrades with electric cooking appliances.

The report also provides guidance to individuals on ways to mitigate the impact of gas cooking.

Recommendations include:

• Make the switch from gas to electric cooking when and where possible, including using small plug-in appliances if they cannot upgrade to electric hobs and ovens.
• Properly ventilate kitchens when cooking, preferably with a functioning range hood that is vented to the outside, by mechanical ventilation, or by opening windows while cooking.
• Install a low-concentration carbon monoxide detector in the kitchen and get an annual gas safety check on gas hobs and ovens.

Professor Frank Kelly, Imperial College London, said: “Cooking on gas adds to the health burden of indoor air pollution, emitting harmful pollutants such as NO₂ that can impact virtually the entire human body. Removing one of the key pollutant sources — gas cookers — from our homes will help create a healthier lived environment and mitigate potential risks to public health.”

Professor Prashant Kumar, founding Director of the University of Surrey’s Global Centre for Clean Air Research (GCARE), said: “Air pollution impacts everyone but is most harmful for vulnerable populations that include babies and children whose immune systems are still developing. The research from CLASP and TNO is consistent with our findings that gas cooking negatively impacts in-kitchen air quality. Electric cooking is the best solution available in the UK to reduce exposure to harmful pollutants released every time we turn on the gas stove.” 

Christine Egan, CLASP CEO, said: “Few people are aware of the harmful risks posed by gas cooking appliances. Electric appliances significantly reduce exposure risks, but there is no mechanism for buyers to compare the efficiency, performance or safety of gas versus electric hobs or ovens. There is an opportunity to transition to cleaner electrical cooking options that are already affordable and readily available across the UK.”

Larissa Lockwood, Director of Clean Air, Global Action Plan, said: “It is a myth that gas is ‘natural’ or ‘clean.’ Shamefully, the gas industry has invested heavily in positioning gas as a safe and preferred cooking option. In part because of these efforts, people are genuinely unaware of the health and environmental risks posed by gas cooking, which are well documented through decades of research. 

However, in a cost-of-living crisis it is not realistic to put the onus on the individual to foot the bill of swapping to an electric oven – we need government intervention. Helping UK homes to transition to cleaner, electric alternatives would be an open goal for the Government to hit a triple-win on air pollution, health and climate goals.”

Contacts

CLASP Europe Director Nicole Kearney (EN) +44 75 4486 5924

CLASP Communications Manager Hannah Blair (EN) +1 225 239 9014

Cooking with gas releases hazardous air pollutants into our homes. Over 36 million people in the UK cook with gas appliances and may be exposed to levels of indoor air pollution that would violate UK outdoor air pollution regulations. When in use, gas hobs and ovens emit carbon monoxide (CO), carbon dioxide (CO₂), and nitrogen dioxide (NO₂) which can linger indoors after use. Research indicates an association between NO₂ exposure and the development of asthma in children. Gas cooking appliances also leak unburned methane, a potent greenhouse gas.

With new research, this report:

• Synthesises the health risks of cooking with gas
• Quantifies the societal cost to the UK
• Identifies how gas cooking undermines UK Government environmental, climate and electrification efforts
• Shares results from a survey of 2000 UK households on their perspectives and awareness of the health risks of gas cooking
• Provides guidance on how to improve air quality in homes that use gas hobs or ovens
• Offers insights on the shortcomings of hydrogen as a cooking fuel
• Gives actionable policy solutions to phase out gas cooking appliances in the UK, in favour of electric alternatives

CLASP and TNO are currently conducting household field studies in the UK to validate the findings in this study. The report will be launched towards the end of 2023.

Visit our Cook Cleaner Europe page to view the TNO reports and additional resources.

All gas cooking appliances release pollutants that are harmful to human health and the environment. Air pollution has been recognised by the European Environment Agency as the biggest environmental health risk in Europe, while the World Health Organisation included it on the list of ten major threats to global health.

Exposure to high levels of pollution is known to cause strokes, heart disease, lung cancer, and both chronic and acute respiratory diseases, including asthma. The impact of gas cooking on the burden of childhood asthma to be comparable to that of second-hand smoke

With new research, this report:

• Synthesises the health risks of cooking with gas
• Quantifies the societal cost
• Identifies how gas cooking undermines environmental and electrification efforts
• Offers insights on the shortcomings of hydrogen as a cooking fuel
• Gives actionable solutions to phase out gas cooking appliances across the EU-27, in favour of electric alternatives

Visit our Europe Cooking homepage to view the TNO reports and additional resources.

Gas cookers release toxic pollutants – such as CO, NO₂ and ultrafine particles – into homes across Europe every day, putting the health of people and the planet at risk. Research shows that children and low-income communities face an elevated risk of negative health impacts, such as increased likelihood to develop respiratory issues like asthma.

“I think of this like a tailpipe in your kitchen – you are burning fossil fuel and combusting it directly in your home – often without ventilation,” said CLASP Senior Advisor Michael Scholand at the International Conference on Indoor Air Quality in June. “40 years of research have shown there is strong correlation between health and respiratory disorders, and indoor air pollution from gas stoves.”

With the advent of cleaner, more efficient cooking technologies like induction cookers, now is the time to take the tailpipe out of EU and UK homes.

With support from the European Climate Foundation (ECF), CLASP launched a new project to accelerate the transition to clean cooking in the region. Our team will collaborate with partners and policymakers to develop an EU and UK specific evidence base on the health effects of gas cooking appliances, initiate discussions on policy solutions, and raise public awareness on the health and climate impacts of cooking with gas.

Learn more about this multi-national campaign on our webpage here. To keep up to date with new research and join the conversation on phasing out gas cooking in Europe, follow our @CLASP_Europe Twitter account and use the hashtag #CookCleanerEurope.

This paper proposes recommendations to policy makers based on a real time data collection exercise carried out in the UK, to analyze the “real world usage” of network connected devices. The paper also maps out how to replicate the project approach and methodology in the US and other regions, to determine whether similar opportunities exist in other areas.

In collaboration with Stricker Associates, CLASP conducted this benchmarking analysis to provide comparison of test procedures and calculation methods used in China, the United Kingdom (UK), and Canada.

Benchmarking China’s refrigerators is important because China’s manufacturing base and market for refrigerators are the largest in the world, and are expanding at a fast pace. At request of Chinese policymakers, CLASP conducted the analysis to provide a method for comparing the allowable maximum daily energy consumption per unit of adjusted volume for China, the UK and Canada on a common basis for household refrigerator-freezers and freezers and to inform the policy revision process in China.

Additionally, this analysis provides complementary data to International Energy Agency Efficient Electrical End-Use Equipment (IEA 4E)’s mapping and benchmarking study for domestic refrigerated appliances. Together, these benchmarking analyses provide detailed comparison on refrigerator energy efficiency policies across nine economies and enable policymakers to identify opportunities to optimize their policies for residential refrigerators based on international best practices.

Defining the maximum allowable energy consumption for refrigerators, refrigerator-freezers, and freezers is challenging because of variations in size, configuration, operating modes, controlled temperature, ambient operating temperature, and power input voltage and frequency.

Although many countries have selected international standards for measuring the performance and efficiency of these products, others have adopted their own systems for rating and labeling these appliances according to their energy consumption. Due to the variations in test procedures, it is difficult to directly compare refrigerator energy performance and efficiency policies across economies.

The comparison of performance of refrigerators requires that the models selected are most common, have comparable functionality, and can be compared on an equivalent performance basis, i.e. operating under equivalent conditions. The results of such performance comparisons can provide insight into the energy efficiency requirements, as well as the efficiencies of products available in these markets.

Benchmarking of appliances in different economies also requires a thorough review of the test methods in order to define a method for making adjustments so as to make the test results directly comparable. Applying the adjustments provides a means for rating the efficiency in each economy against one another, revealing the actual differences on a common basis.