Cabin Air Quality in Cars

Cabin air quality is the measure of the air quality within the vehicle itself. While you sit in traffic and drive through cities in towns, your vehicle should filter out the harmful emissions to keep you safe.

Why is Cabin Air Quality important?

Cabin air quality is the measure of the quality of the air within a vehicle. Cabin air quality is not just about comfort, but also safety.

High levels of cabin carbon dioxide are associated with stale air, but also it is a sign of the cognitive effects that might lead to increased reaction times and drowsiness. Particles can not only smell bad, but exposure to them is often associated with chronic health effects and increased morbidity.

Particles and carbon dioxide exposure are not regulated inside the vehicle cabin, even though they are at the tailpipe. This is despite the increasingly well understood link between particle exposure and respiratory and other health effects and the tendency of CO2 exposure to lead to cognitive impairment at elevated concentrations.

Poor cabin air quality means drivers and passengers are being exposed to potentially dangerous levels of pollution.

What affects Cabin Air Quality?

Air coming into the vehicle should be filtered, however, there are currently no regulations for how effective these filters need to be. Some cars will filter just 1% of pollutants from the air, while others are able to filter 90%.

Cabin air quality can be affected by a range of factors, such as:

  • Quality of the basic air filtration system
  • Presence of more advanced technology such as climate control and active carbon filters
  • How the car is used – traffic and urban driving will increase exposure to higher levels of pollution
  • Maintenance of the filtration system

Cabin Air Quality in Leading Vehicles

As cabin air quality isn’t yet regulated, manufacturers aren’t required to measure their cabin air quality or effectiveness of their air filtration systems.

Safety tests conducted by Emissions Analytics in 2018 found a huge level of variation in the ability of some leading models to filter out harmful pollutants.

For example, the Toyota C-HR had cabin air quality as bad as the polluted air outside, whereas the Mercedes E-Class filtered 90% of the harmful pollutants.

At AIR we are taking this further. We are working towards testing and reporting on the cabin air quality of some of the UK’s leading vehicles. We will be publishing our results in the AIR Index so consumers, policy makers and fleet owners can make informed decisions based on the ability of vehicles to protect drivers and passengers from harmful pollution levels.

How to Improve Cabin Air Quality

Cabin air quality has been a widely neglected measure despite being both an issue of safety and an environmental concern.

In order to improve cabin air quality, we’ll need to see:

  • The introduction of cabin air quality regulations
  • A simple and easy way to measure and check the cabin air quality of a vehicle
  • Reduction of pollution and harmful emissions on our roads
  • Commitment from car manufacturers to produce and introduce clean air technology

Cabin Air Quality Ratings
(Coming Soon)

As part of the AIR Index, which rates vehicles based on their comparable NOx emissions levels and the levels of on-road CO2, AIR will publish Cabin AIR Quality rating, a based on the presence of pollutants inside a vehicle recorded during on-road tests.

It has been created to inform and empower vehicle buyers, policy makers and fleet managers with the real facts about safety when making choices about car purchase, and passengers who may use the vehicles as taxis, for example.

As with NOx and CO2, the Cabin AIR Quality rating will be a simple A-E colour-coded rating, showing the difference between high and low quality cabin air based on the levels of pollution present in urban driving.