Ad description

The website for the outdoor clothing and equipment retailer Mountain Warehouse,, seen in October 2016, advertised a walking boot called “Hurricane IsoGrip Waterproof Boot”. Further text in the description box stated “Waterproof - Our IsoDry membrane allows your feet to breathe whilst allowing moisture to escape the shoe, keeping you comfortable when on the move.”


The complainant, who found that the boot did not prevent their feet from getting wet when walking in wet outdoor conditions, challenged whether the claim “waterproof” was misleading.


Mountain Warehouse Ltd said that most waterproof footwear was only tested up to 20 mm above the feather line – the point in the shoe where the boot flexed and the shoe membrane took the most pressure. They pointed out that a separate web page of the website made that clear with an explanation and diagra​m. They also said that the product’s swing ticket made clear that the boot was only waterproof 20 mm above the feather line.

Mountain Warehouse said that the boots’ effectiveness was severely hampered in deep puddles and wet environments such as long grass without the support of gaiters. They said a hiking boot of any size and description will have parts that were susceptible to water ingress such as over the top of the ankle, through the laces and through the capillary action into sock. They believed that that would be understood by consumers, who could decide whether to choose between a hiking boot which was waterproof during normal usage and a wellington boot.

Mountain Warehouse provided a test report by a product testing and certification company that showed that the product had passed the TM230 “water penetration for whole shoe” test, where no water penetration had been found after 15,000 cycles. The water level was 20 mm above the feather line, and the flexing angle was 25 degrees. They said that the TM230 test was the industry standard test for waterproof footwear, and was used extensively in the outdoor industry. They provided an email from the manufacturer of the boot, who said that it was an industry-wide practice for “waterproof” boots to be tested to 15,000 cycles, and at a water level of 20 mm above the feather line. The advertiser said that the test’s designers had confirmed that verbally to them. They also provided an extract from the ISO specifications on the test method for personal protective footwear, which was “applicable to all types of shoes and boots”. The test specified a requirement of 4,800 cycles in a water level set at 20 mm above the feather line.

Mountain Warehouse provided correspondence with the product testing company, whereby a representative said that their industry guidelines to class an item as waterproof was when there was no water penetration after 100,000 cycles. The representative said that the test was normally to the feather line, but that could be altered based on how the shoe would be used and the claims being made. They provided a link to an article about the test on the test designer’s website. They said the article showed that for personal protective boots, the TM230 test could be used to 4,800 cycles, while 300,000 cycles should be used for military boots. Another link on the test designer’s website that they provided showed that they also advised around 300,000 cycles for a wet weather boot, in which the water level was set at a level where the shoe’s vamp was immersed.



The ASA considered that consumers would understand the claim “waterproof” to mean that the boot would prevent the wearer’s feet from getting wet when walking in the outdoors, including in wet conditions.

We noted that the boot had passed an established water-resistance test for footwear, which placed part of the boot into a water bath using a machine that simulated the effect of walking. The part of the boot placed into the water was from 20 mm above the feather line to the sole of the boot (roughly the bottom third of the boot). No water penetration was found in the boot after 15,000 cycles.

We understood the test was designed for all types of footwear, in which it was recommended that the water level and number of cycles should be adjusted depending on the intended use of the footwear. The evidence provided by Mountain Warehouse indicated that a test of 4,800 cycles at 20 mm above the featherline could be used on general personal protective footwear. They did not, however, provide any documentary evidence to show that only 15,000 cycles was required for “waterproof” outdoor footwear. Furthermore, correspondence provided by the advertiser indicated that the company that conducted the test advised 100,000 cycles to use the term “waterproof”, while the test designers advised around 300,000 cycles for both a wet weather boot and a military boot.

The test designers also advised setting the water level so the shoe’s vamp (the upper front part of the boot) was immersed in water for wet weather boots, which appeared to be a higher level than 20 mm above the feather line used by Mountain Warehouse. We also considered that the 20 mm water level was not sufficient because it was likely that more than the bottom third of the boot’s exterior would come into contact with water when walking in wet outdoor conditions.

Because the advertiser did not provide any evidence that the water-resistance test had been conducted using a number of cycles in line with the industry standards for a "waterproof" outdoor walking boot, and because only the bottom third of the boot had been tested, which was not sufficient for an outdoor walking boot, we concluded that the claim “waterproof” 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) and  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).


The ad must not appear again in its current form. We told Mountain Warehouse Ltd not to use the claim “waterproof” unless they held sufficient evidence to support their claim.

CAP Code (Edition 12)

3.1     3.7    

More on