I have a product called Encapuguard Green that does a great job and is safe. Encapuguard Green is formulated following guidelines established by the US EPA Design for Environment Program.
Encapuguard Green replenishes the soil resistance and stain protection that came with your new carpet.
How Encapuguard Green Works
Dirty Carpet Fibers – As your carpet fiber surfaces become worn and walked upon, the surface is now porous and it attracts and traps more sand, dirt, pollen, dust mites and their feces, along with everything else your family has brought home from the outside world.
Worn Carpet Fibers – Cleaning will remove the soil and reset the nap on many carpet fibers. However the scratches are still on the fiber.
When Encapuguard Green is applied after a professional cleaning, the porous openings in your carpet fibers are filled in, leaving a smooth, like-new surface. Every time you vacuum, all the sand, dirt, pollens, dust mites and their feces are whisked up by your vacuum instead of staying in the pores. It basically replaces the stain and soil protection that has worn off since it was new or last applied. It does have to be replaced every cleaning or two but it is a fairly inexpensive carpet protector that works. Its drawback would be that it makes the carpet a little stiff until it has been vacuumed. The plus side : A safe product that can be applied in your home at a reasonable price.
*Though Encapuguard Guard does not contain solvents, PFOA or any known harmful chemicals. Foot traffic should be limited until carpet is fully dry. For more information check our FAQ.