Ad description

A website for Hyundai,, seen on 30 January 2021, included text which stated “All-New NEXO” and “Introducing the next generation of fuel cell vehicles: All-New NEXO. A car so beautifully clean, it purifies the air as it goes”.


The complainant challenged whether the claim “A car so beautifully clean, it purifies the air as it goes” was misleading and could be substantiated.


Hyundai said that the Hyundai NEXO was a hydrogen-powered car that produced its own electricity by combining oxygen and hydrogen within a fuel cell. They said a clean supply of air was essential to provide the oxygen in order for the fuel cell to operate because the air contained gases and particles that would damage the fuel cell. They said the NEXO contained an air supply system to manage and clean the air supply. Hyundai provided an illustration that demonstrated how the components acted to filter the air. The air filter removed 97% of fine dust and gases, such as sulphur dioxide and nitrous oxides. The humidifier and fuel cell themselves also acted to remove ultrafine dust.

Hyundai said that overall, the air purification system filtered gases and 99.9% of very fine dust, which was then retained in the car. That meant purified air was expelled from the system. As such, they said the claim “purifies the air as it goes” did not relate to the lack of traditional exhaust gases but was based on the air purification system on board the vehicle. Hyundai said that the NEXO did not specifically filter and clean particulates from its own brakes and tyres. However, they said the air that was drawn into the car may include those particulates, as well as particulates from other vehicles.



The ASA considered that the claim “A car so beautifully clean, it purifies the air as it goes” would be understood to mean that the car overall had negligible environmental impact and would remove impurities from the air as it was driven, such that no impurities caused by driving it would remain in the air. The complainant had raised concerns because they understood that, although the car would not release exhaust fumes like a traditional combustion engine, it would still release particulates as a result of brake and tyre wear.

We acknowledged that there were air filtration systems in place within the Hyundai NEXO, which would filter the air before it was used in its hydrogen fuel cell. However, we understood particulates from brake and type wear would still be released into the air and would not necessarily be removed by the car, unless they happened to pass through its air filtration system. We understood that particulates from brake and tyre wear were a significant source of air pollution from vehicle use. Because we considered the claim “A car so beautifully clean, it purifies the air as it goes”, as it was likely to be understood by consumers, had not been adequately substantiated, we concluded the ad was misleading.

The ad breached CAP Code (Edition 12) rules  3.1 3.1 Marketing communications must not materially mislead or be likely to do so.  (Misleading advertising),  3.7 3.7 Before distributing or submitting a marketing communication for publication, marketers must hold documentary evidence to prove claims that consumers are likely to regard as objective and that are capable of objective substantiation. The ASA may regard claims as misleading in the absence of adequate substantiation.  (Substantiation),  11.1 11.1 The basis of environmental claims must be clear. Unqualified claims could mislead if they omit significant information.    11.2 11.2 The meaning of all terms used in marketing communications must be clear to consumers.  and  11.3 11.3 Absolute claims must be supported by a high level of substantiation. Comparative claims such as "greener" or "friendlier" can be justified, for example, if the advertised product provides a total environmental benefit over that of the marketer's previous product or competitor products and the basis of the comparison is clear.  (Environmental claims).


The ad must not appear again in the form complained of. We told Hyundai Motor UK Ltd not to state or imply that no impurities caused by driving the Hyundai NEXO would remain in the air, unless they held adequate substantiation to demonstrate that was the case.

CAP Code (Edition 12)

11.2     11.3     3.1     3.7     11.1    

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