I was recently asked a question, and I thought it was a great question, so I thought I'd respond here on the Clean Files Blog so that everybody can benefit from the answer. The question was "How do you remove blood stains from cotton shirts? I use hot hot water to wash, but it seems to never lift all the way out."
Blood is a water-based protein stain, so you will use water and an alkali to remove it. Most laundry soaps are slightly alkaline so we'll start there. Using hot water to clean 100% cotton white shirts is a generally a good idea, but not when removing blood stains - stick with cool water here. If the blood stain is still there after washing, leave the shirt wet and move to the next step.
If after washing the blood spot remains, drop a few drops of clear (non-sudsy) ammonia on the wet shirt (do not apply to a dry garment). Ammonia is a strong alkali and has a very strong smell, however in household concentrations it isn't dangerous as long as proper care is taken. Let the ammonia sit for 15 minutes then try washing again. If the stain is still there, leave the shirt wet and move to the next step.
If the blood stain remains there is one more thing you can try at home if the shirt is all white and is 100% cotton, not a blend. If this shirt isn't all white or 100% cotton, you can follow this step but understand damage to the shirt may occur. First make sure the shirt is wet, and then place it into this hydrogen peroxide mixture. Mix 2 ounces of 3% hydrogen peroxide (the commonly available kind in the brown bottle) per gallon of 100 F water and let sit for 30 minutes to 3 hours. Make sure the shirt stays fully submerged and turn over a few times using a piece of wood or plastic (not your hands). Now wash in cool water and air dry. How did it turn out?
If the blood stain still didn’t come out or if you don’t feel comfortable with in home spot removal, your dry cleaners has more tools available (such as an enzyme soak) to help remove blood stains.
Photo credit: chadmiller