I needed a polypropylene container to make soap with alkali. I was thinking of using bowls or small jugs so I can pour liquids in. I ended up buying us a small set as well as this set and am very happy with my decision to buy this one. Not only is Polypropylene safe for soap making, I know it will last a long time and appears to be very durable and well made. I can also mix the soap directly in some of the larger containers with an immersion blender, so I end up washing less dishes! These pitchers have many other uses. I put the largest one under the sink and fill it to the brim to fill the Berkey water filter. The largest pitcher holds over a gallon while maintaining structural integrity. The only negative is the price as paying $35 for plastic seems a bit high but if you are a serious soap maker this is a great long term investment!