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Ask Dr. Laundry

Ask Dr. Laundry

Using Bleach to Remove Dark Urine Stains on Carpet

By Dr. Laundry April 20, 2017

Q. When we removed carpet pet urine stains, they were dark in places. Wonder if bleach can be used?

—Sherry

A. Hi Sherry;

Do you know if your carpet is a synthetic (nylon, olefin/polypropylene, polyester) or if it is wool? If it is wool, call a carpet cleaning service sooner than later so they can properly treat the stain. Depending on the age of the carpet and how long it’s been since it’s been cleaned, you may need to have the entire room cleaned so you don’t end up with a very clean section where the stain was pretreated and cleaned.

If your carpet is a synthetic, there are lots of different products you can try (I wonder what you have used so far?). Before our very old lab passed on, I found Clorox® Urine Remover to be very effective at getting rid of her urine accidents on not just carpet, but also hard surfaces. With carpet it gets sprayed on, saturating the stain, and then after 3 minutes you use a clean DAMP absorbent towel to blot the stained area to rinse it. Never soak a carpet with water — it’s bad for the subfloor.

Finally blot the treated area dry with a clean dry towel until no more moisture gets onto the towel. You may need to apply pressure with colorfast heavy objects (books are good as long as they won’t bleed color onto the towel and through to the carpet) to get it all.

I wouldn’t use Clorox® Regular-Bleach1. You absolutely can’t if the carpet is made of wool, and synthetic carpet manufacturers typically recommend against it as well.

I also wonder if you ended up with the dark stains immediately after trying to remove the urine stains or if they appeared over time. If they showed up a little later, then there was probably some product residue left over from whatever you used to originally treat the stain. The residue usually includes the cleaning agents, which then act as dirt magnets and actually attract dirt! If that’s the case, you may want to rent a carpet cleaning machine to really deep clean not just the stained area but the entire room so you don’t end up with a super clean spot.

I hope this is helpful. Please let me know if you have any other questions, and thanks for writing!

—Dr. Laundry