A laundry ball is a product that is promoted as a substitute for detergent. Producers of laundry balls have been criticised for making pseudoscientific claims about how these balls work and the extent of their benefits. [1] The product is often sold by participants in multilevel marketing schemes.[1] While many people report that these balls work, the benefits are as good or even worse as washing without any detergent.[2][3] Most of the effect can be attributed to the mechanical effect of the ball or to using hot water instead of cold water.[2][4]
There are several shapes of laundry balls: laundry disks, globes, spheres or doughnuts.[5] The balls carry certain components inside, like ceramic pieces, magnetic material or activated water .[5] Manufacturers claim that these components have certain effects on washing efficacy, although studies don't show any difference between the different types of balls.[5] Some balls also contain pellets of detergent or other ingredients.
Claims vary between products. Some claims are not backed by science, while others are an exaggeration of benefits. Balls which contain detergents may offer more cleaning power than water alone since their ingredients are comparable to normal washing powder, but in smaller quantities. It is claimed that conventional washing powder manufacturers recommend using more powder than is necessary, and that these powders contain unnecessary fillers or fragrances.[2] Critics question whether the amount of detergent released by these balls is sufficient to generate significant cleaning effects.[6][7]
Some manufacturers claim that the components inside their balls emit far infrared rays, which are claimed to reduce the surface tension of water and facilitate washing.[5] The claim of emitting infrared is not false, as all materials emit far infrared waves at room temperature, in other words, heat radiation.[2] It is also true that heating reduces the surface tension of water, but the effect of the radiation emitted by the balls is negligible compared to the radiation emitted by the internal walls of the washing machine or by the water, specially if it's hot water.[2]
