It's an environmental issue.
The science:
A new study shows that delicate wash cycles pull 800,000 more microplastics (which are pieces fewer than five millimeters in length) into the water than regular cycles do. That's potentially twice as much as what's released in regular loads, adding to the growing concern of plastic pollution in the oceans.
Expert insight:
It was previously believed that the faster the water moved inside a washing machine, the more microplastics would be released from certain types of fabric. By that logic, regular cycles would be most harmful.
The new research shows that it’s actually water volume, not speed, that determines how many fibers are pulled from your clothing, explains study author Max Kelly, a Ph.D. student in the School of Natural and Environmental Sciences at Newcastle University in England. Delicate cycles use the most H2O, making them worse for the environment in more ways than one.
The bottom line:
It’s okay to wash naturally derived fabrics like wool and silk on delicate since they’re biodegradable, Kelly says. Items made with synthetic materials, such as nylon and polyester, should always go in a regular load.