How does your evidence measure up? ASA upholds complaint about exaggerated claims of water purification

United Kingdom

The ASA upheld a complaint against Microlyscs t/a CrazyCap following a complaint that its Facebook post, claiming that its bottle cap product killed pathogens, was misleading and could not be substantiated.

The claim

A post on the CrazyCapbottle Facebook page, seen in July 2020, stated “CrazyCap’s deep UV water purification is effective against bacteria, viruses, and pathogens. It prevents a wide range of waterborne illness[sic] by effectively killing 99.999% germs from any questionable water source”.


The complainant challenged whether CrazyCap’s claims were misleading and could be substantiated.

CrazyCap’s response

CrazyCap explained that its CrazyCap product was a bottle cap that used UVC light, which worked by entering microbial cells and making the cells no longer viable. CrazyCap compared that process to boiling water to make it safe for consumption. CrazyCap provided two lab reports and explained that the product was tested via a third-party nationally accredited and certified microbiological lab. CrazyCap also provided information about a study on the effectiveness of UV irradiation for pathogen inactivation, a news article and an article about a study into the efficacy of UVC.

The ASA’s ruling

The ASA upheld the complaint. The ASA considered that consumers were likely to interpret the claim “CrazyCap’s deep UV water purification is effective against bacteria, viruses, and pathogens” and it “prevents a wide range of waterborne illness by effectively killing 99.999% germs” to mean that the product was able to successfully kill bacteria, viruses and pathogens in water. In the absence of further qualifying information, the ASA considered that consumers would understand the claim to be in relation to all bacteria, viruses and pathogens.

In considering the evidence, the ASA noted that the cap had two settings: a “Crazy” mode of 120 seconds of exposure and a “Normal” mode of 60 seconds of exposure. CrazyCap provided two lab reports testing the product, each testing a different species of bacteria. The ASA found that as the first test was conducted on an iPad, it did not assess the CrazyCap’s efficacy in water and, therefore, considered the report to be less relevant in substantiating the claim.

By contrast, the second test was conducted in water using the Normal mode for one- and two-minute exposure times, and the Crazy mode for two- and four-minute exposure times. The results showed 99.91% and 99.99% of bacterial colonies were destroyed for the Normal mode one- and two-minute exposure and the Crazy mode exposures showed 99.999% and 99.9996% for the two- and four-minute exposures. Although the ASA acknowledged that consumers could use multiple cycles if desired, the Crazy mode cycle was only 120 seconds. As such, the ASA considered that the four-minute testing for both lab reports was less reflective of how the product was likely to be used by consumers.

The ASA further noted that all evidence submitted only demonstrated the CrazyCap being used on two species of bacteria. No evidence in relation to viruses or any other pathogens was provided.

Finally, the ASA also found that the additional articles provided by CrazyCap discussing the effect of UV radiation more generally did not relate to the CrazyCap product, and it was unclear if the technology and mode of delivery used in the articles was reflective of the product itself.

As such, the ASA found that CrazyCap had not provided sufficient evidence to substantiate its claim as consumers were likely to understand it. The ad was therefore misleading and in breach of rules 3.1 (misleading advertising), 3.7 (substantiation) and 3.9 (qualification), and 12.1 (medicines, medical devices, health-related products and beauty products).


There are many upheld ASA complaints in relation to health-related products for which the claims made are wild and have no basis in fact. However, in this complaint, the advertiser produced what appeared to be reasonably robust evidence that, even when used on one- and two-minute cycles, the product killed almost all of the pathogens that were the subject of the test. The complaint appears to have been upheld mainly because, instead of making only claims that could be substantiated on the available evidence, the advertiser went further and claimed that their product worked on “bacteria, viruses, and pathogens” generally.

This ruling is therefore a reminder of the importance of making sure the evidence in hand substantiates the actual claims made. Testing methodology must be robust, withstand scrutiny and be representative of the instructions for use of the advertised product. Further, the evidence submitted and relied upon must relate to the product being advertised.

Co-authored by Stuart Helmer and Aysha Kaplankiran.