Desk chairs have norms, so they meet Health and Safety legislation. This is important for the wellbeing of employees. NPR 1813 is one of those Dutch norms. This abbreviation stands for Nederlandse Praktijk Richtlijn (Dutch Practical Guideline). This Health and Safety norm is based on the taller average body length of Dutch people. If you buy a desk chair which meets the NPR 1813 norm, it's guaranteed to be ergonomic. This reduces the chance of physical aches if you work while sitting down for hours a day. Whether you work at the office or at home, you need a desk chair which adjusts to your body length.