How Clean is Clean?
The Science of Cleaning
People often ask How clean is clean? When can we say that a surface is clean enough?
Is it good enough when it looks visibly clean? Or do we need to worry about what we cannot see? A group of scientists have been asking themselves these questions. Although the answer to How clean is clean? is a bit complicated, the short answer is: it depends! The website How clean is clean? explores the science of cleaning and how these questions can be addressed.
Cleaning is something that we do every day, often without thinking too much about it. We wash our hands, brush our teeth and do the dishes, for instance. Cleaning also happens at work. To make food that is safe to eat, restaurants and food manufacturers follow strict cleaning protocols. The same happens in many other areas: to produce pharmaceuticals, cosmetics, or even the tap water we drink… Cleaning is also important in public spaces. We all enjoy a clean environment. However, we tend to only notice it when it is not clean.
Although cleaning is often perceived as a chore, the science of cleaning is actually really fascinating! To understand how cleaning works, scientists have examined what we know about cleaning. The reason why the answer to How clean is clean? is it depends is because the answer changes with what we want to clean. With the Covid-19 pandemic, we have all learnt that in order to keep our hands clean, we need to wash them thoroughly with soap and water or use alcohol gels. However, when we want to clean our streets, it is probably good enough when they look visibly clean.
At a recent workshop, scientists have also found that there are similar scientific principles behind many seemingly different applications. This is important because once we understand these scientific principles, we can improve the numerous cleaning methods that we need every day. We can make sure that the things we want to clean are indeed clean enough, but without using too much water and chemicals so that cleaning is sustainable. These are some of the main conclusions from the workshop, which are summarized in a Roadmap document. The Roadmap highlights a way forward to bring scientific advances on cleaning and decontamination problems into the real world.