Science Technology Dyson Reveals the Dirty Truth About Hand Dryers By Derek Markham Writer Derek Markham is a green living expert who started writing for Treehugger in 2012. our editorial process Twitter Twitter Derek Markham Updated October 11, 2018 CC BY 2.0. Ben Husmann Share Twitter Pinterest Email Science Space Natural Science Technology Agriculture Energy Those warm air hand dryers may just be blowing bacteria-filled air back onto your clean hands. The Dyson Airblade hand dryer, with a HEPA filter, is said to remedy that. The closer we look at the items we touch every day, from our phones to our doorknobs to our beards, let alone surfaces in public places, the more it's apparent that our environment isn't nearly as clean as it looks. And it may be that even after washing our hands in the bathroom, they might end up just as germ-laden as before if we use one of those warm air hand dryers that are a fixture in public bathrooms, according to recent testing done by the research team at Dyson. The air in bathrooms could be filled with viruses and bacteria that have gone airborne due to the action of flushing toilets, and because conventional hand dryers recirculate this air without filtering it, drying your clean hands under one could be spreading harmful microorganisms back onto your body. In addition, because wet surfaces can be a more efficient vector for bacteria than dry surfaces, using conventional hand dryers that rely on evaporation may not be not nearly as hygienic as we think. According to Dyson, however, its Airblade system, which incorporates a HEPA filter, can remove 99.97% of bacteria- and virus-sized particles from the air intake before the air is blown onto hands. In addition, because the system doesn't heat the air, but instead relies on high-velocity air streams (430mph), the Airblade quickly scrapes the water from hands "like a windscreen wiper," and leaves hands completely dry afterward. Here's a quick video that illustrates this weakness in conventional hand dryers: The company claims that their Airblade units use up to 80% less energy than conventional hand dryers, and can completely dry hands in just 12 seconds (compared to up to 43 seconds for other models), so these high-tech dryers could be not only helping to improve sanitation hygiene and public health, but also saving money and energy as well. As part of Dyson's promotional efforts for the Airblade hand drying systems, the company is opening nominations for local commercial restrooms to win three free Airblade units (valued at $2,397), with entries being taken between June 1, 2015 and June 30, 2015.