Have you ever had the o-ring on your garden hose split and leak everywhere? Annoying, isn’t it? If your first thought is that it’s due to a poor quality of rubber, think again. Many o-rings are made from NBR (nitrile), because the large majority of o-rings are used in applications to seal against oil – which NBR excels at. Unfortunately, it also degrades quickly in sunlight. Not a poor rubber quality, then – just the wrong material for the hose application. We take a more detailed look at what we mean by rubber quality and how to test the quality of rubber.