When I ran a chemical reuse website, the request I got over and over was for help with setting up a project to reuse little bars of soap from hotels. So I got to wondering what kind of redesign could be applied to soap bars. See below.

When it comes to bar soap used in homes however, there is a neat way to increase the reuse.

As usual, it involves changing one of the neglected design parameters to increase reuse. In this case, it is the shape of the bar. What if one side of the bar had a recess in it that was made to receive the typical, small, used up former soap bar? In other words, when a bar becomes too small to use, the homeowner would open up a new bar, wet it up, and then place the wet, soapy, small residue bar into that recess. As soon as the two had a chance to dry together, they would stick. Subsequent wettings just add to the adhesion until the two are welded together.

I do this anyway, today, but with smooth or flat or curved surfaces it is difficult and most people wouldn’t bother. If a pre-engineered recess were available, the tendency for the two pieces to slide apart would become less annoying and everyone could use the trick. I’ve noticed that Irish Spring soap is already made this way but I wonder if they were thinking about Zero Waste.

A trick to getting the two pieces to stick tight the first time is to hold them together with a clamp. Here is a picture of a small piece of Irish Spring soap being fused to a new bar:

This works so well that it answers the question of how to reuse hotel bars. Make a matrix  or jig to hold them in a column, wet them and then put some kind of clamp or heavy weight on them to fuse them all together.

Of course there is a missing link. A study would be needed to determine the typical shape of a used bar of a soap and the best recess for holding it. This is a very small project. Some soap molds would need to be changed and the packaging would need to announce a new Zero Waste reuse ability. More and better advertising for Zero Waste.

Now in 2010 comes a new charity actually focusing on this problem. Composed of companies in the hotel business, Clean the World collects unused soap bars from hotels and distributes them to kids with sanitation deficiencies. I haven’t learned what they can do for kids without access to clean water but I guess it’s a start. From Clean the World, here is their story:

Every day in North America, thousands of hotels discard millions of pounds of soap and shampoo. These products often end up in already overflowing landfills and contaminate fragile groundwater systems.Impoverished people around the world die every day from acute respiratory infection and diarrheal disease because they have no soap. The death toll is staggering. Each year more than five million lives are lost to these diseases with the majority of deaths being among children less than five years old. Studies have shown that simple hand washing substantially reduces the spread of these diseases. Unfortunately, the essential items for proper hand washing are unobtainable for millions of people worldwide. Clean the World gets soap to people who really need it. In an effort to prevent these needless deaths from occurring, Clean the World distributes recycled soap products, along with appropriate educational materials, to impoverished countries worldwide, and to domestic homeless shelters.