Ad description

A TV ad for Dyson, seen on 14 May 2017, began with a woman at the window of her house, looking visibly concerned. The ad cut to a car exhaust producing green vapour. The word “Exhaust Particles” appeared above the exhaust. In the background a voice-over said, “What could be worse than the pollution outdoors?” The woman closed the door and returned to the house. The voice-over then said, “Well the pollution indoors can be up to five times worse where gases and microscopic particles can build up." The camera followed the woman as she walked into the kitchen where a number of appliances let off purple and green vapour, including household cleaning products next to a fridge, three potted plants and a hob. Text appeared above those items that indicated which pollutants they released – these were benzene gas, pollen particles, formaldehyde gas and allergens. The woman was then shown holding a smart phone. An app stated the word "Poor" in reference to the air quality in her home. The camera then cut to a shot of the Dyson Purifier Heater, an air filtration device, which sucked in the coloured vapour. The voice-over said, "But Dyson's Purifier Heater uses a HEPA filter to capture particles and activated carbon to capture gases while warming or cooling you."


Three complainants, who believed the ad exaggerated the health risks posed by pollution levels in a typical domestic kitchen, including by drawing a comparison with a car exhaust, challenged whether the ad’s claims were misleading and could be substantiated.


Dyson Ltd said health risks were not mentioned in either the ad's voice-over or the visuals. They said the intention of the ad was to increase public awareness concerning indoor air pollution.

Dyson said their claims regarding awareness were supported by a paper from the European Respiratory Journal that stated concentrations of some air pollutants were two- to five-fold higher indoors than outdoors. Dyson also provided a study by the US Environmental Protection Agency (EPA) which stated "indoor air levels of many pollutants may be 2-5 times and occasionally more than 100 times higher than outdoor levels". The EPA report stated indoor air pollution was an issue that required public attention and highlighted several common sources of indoor air pollution including gas hobs, flowering plants and domestic cleaning products.

Dyson said the ad's mention of a "build-up of microscopic particles" was meant as a statement of fact. They included a copy of a report from US research institute SRI International that showed common household pollutants such as plant spores, pollen, tobacco smoke, atmospheric dust and black carbon could build up in the home.

Dyson also sent a report by the Royal College of Physicians and highlighted a statement that stated, "[t]here are few regulatory controls on indoor pollution, apart from building regulations. The drive to reduce energy costs, by creating homes with tighter ventilation, could be making the situation worse". They also provided a study from 2014 that looked at the mass concentration of pollutants sized 2.5 microns (known as particulates) in "home" and "private residential" environments. The research found the build-up of particles was higher in both of those environments than "outdoor other".

Dyson said they did not intend to exaggerate the health risks of indoor air pollution by drawing a comparison between indoor air pollution and the car exhaust fumes. They said the visual comparison between the two was meant to emphasise the amount of pollutants in the home, while the question "What could be worse than the pollution outdoors?" was intended to highlight the lack of consumer understanding concerning indoor air pollution. Dyson offered to remove the shot of the car exhaust fumes from the ad.

Clearcast said the product was advertised as an air purifier and that Dyson were keen to establish that it removed gases as well as particles from the air. They said Dyson had previously advertised a similar model which claimed to remove particles and had demonstrated, using recognised test methods, that the product's activated carbon filter was capable of capturing gases. Clearcast said there was no suggestion of any health benefit in the ad and that if there had been, it was unlikely they would have approved it. They said they approved the ad in the same way they approved ads for water filters that also claimed to remove impurities but did not seek to make health claims. They said the comparison between the indoor and outdoor pollutants was not a direct comparison because the car exhaust fumes disappeared into the air, which was something that did not happen in domestic settings.



The ASA considered the similarity in the colour of the indoor and outdoor fumes would be understood by consumers as a comparison. We noted the ad began with a reference to a familiar everyday pollutant that was known to have an effect on public and environmental health. The voice-over then said, “What could be worse than the pollution outdoors?” In this context, we considered that, based on consumer understanding, the word “worse” referred to effects on health or the environment. We also considered the look of concern on the female character’s face, the use of the word “worse” in the voice-over, the word “poor” on the phone screen and prior knowledge of the damaging effects of outdoor pollutants to health would therefore lead consumers to understand that indoor pollutants were more damaging than outdoor pollutants.

We noted the reports that were provided to us by Dyson demonstrated indoor air pollution was both measurable and a concern to public health. However, the reports only discussed the presence and types of indoor pollutants and, although some of those reports did discuss the impact on health, they did not state whether they were more damaging to health than outdoor pollutants. We considered that the reports were not relevant in determining the comparative damage of indoor and outdoor pollutants and that the evidence was therefore not sufficient to demonstrate that indoor pollution was more damaging than outdoor pollution.

We therefore concluded that the ad was misleading.

The ad breached BCAP Code rules  3.1 3.1 Advertisements must not materially mislead or be likely to do so.  (Misleading advertising) and  3.9 3.9 Broadcasters must hold documentary evidence to prove claims that the audience is 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).


The ad must not appear again in its current form. We told Dyson Ltd not to make implied health claims in their ads in the absence of adequate evidence to support such claims.


3.1     3.13     3.9    

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