Noticed these dark grey bands forming along the edges of the carpet in every room near the baseboards. We don’t wear shoes inside, but the perimeter keeps turning black no matter how much I vacuum. Is

distinguishing between harmless dirt and potentially harmful mold, while also offering solutions for both cleaning and prevention.

The dark lines forming along the edges of your carpet are often known as ‘filtration soiling.’ This phenomenon occurs when air passes through the carpet, leaving behind dust, dirt, and other particulates that get trapped in the carpet fibers. Over time, these particles accumulate, resulting in the noticeable black lines.

Filtration soiling is more common around the perimeter of rooms, under doors, and along