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In-vehicle pollution: UNECE recommendation updated to measure harmful exhaust gases entering the cabin

Vehicles’ interior air quality has steadily improved over the last decade, with the use of materials emitting less toxic components into the air.


The updated recommendation adopted today by UNECE’s World Forum for Harmonization of Vehicle Regulations (WP.29) now includes a procedure to measure exhaust gases entering the vehicle’s cabin through ventilation systems.


The new internationally-harmonized procedure measures the concentration of three toxic gases (nitrogen oxide (NO), nitrogen dioxide (NO2) and carbon monoxide (CO)) in the cabin under two test conditions: when the vehicle is stationary with the engine idling, facing against the wind direction; and when the vehicle drives at a steady speed of 50km/h, to simulate driving in a city environment.


By increasing consumer knowledge of interior air quality when choosing a vehicle, the new recommendation incentivizes manufacturers to improve design and efficient ventilation systems to minimize exhaust gases entering the cabin.


Countries are invited to transpose the recommendation into national legislation within the framework on the UN agreements on vehicle regulations hosted by the World Forum for Harmonization of Vehicle Regulations (WP.29).


The Russian Federation has announced that it plans to update the interstate GOST 33554-2015 “Motor Vehicles. Content of pollutants in the interior of driver’s cabin and passenger compartment. Technical requirements and test methods” in compliance with Mutual Resolution No. 3 in the course of 2021.


The new recommendation builds on cooperation between experts at UNECE since 2015 to develop harmonized procedures to measure in-vehicle air quality. Mutual Resolution No. 3 published in 2018, focused on the harmonized procedure to measure emissions from interior plastics (plastics, adhesives, cleaning products, plasticizers, paint, sealers, lubrication compounds, etc.). The so-called "new car smell" was often linked to the presence in the vehicle’s cabin of substances referred to as Volatile Organic Compounds, composed of acetaldehyde, acrolein, benzene, ethylbenzene, formaldehyde, styrene, toluene and xylene, which are harmful to human health.


To further protect the safety of vehicle occupants, experts are now focusing on procedures to assess the effectiveness of the filtration by the vehicle's ventilation system of other harmful substances, notably particulate matter and gaseous components.

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