Do Blood Stains Go Away from Concrete Flooring?
Firstly, it is to understand that concrete is a porous material, meaning it has many small holes and spaces within its structure. And secondly, when blood comes into contact with concrete, the proteins and iron in the hemoglobin can seep into these pores. Once the blood dries, it can be quite difficult to remove because the iron reacts with the oxygen in the air and becomes oxidized, causing the stain to set.
To actively remove or minimize a blood stain on concrete, it's best to clean it as soon as possible. (This type of cleaning should be performed by a professional biohazard cleanup crew.)
However, if the blood stain is old and has been set for a long time, complete removal can be challenging. In such cases, even with vigorous cleaning, some discoloration might remain.
So the answer is that once a stain is set by blood on concrete flooring, it does not go away. A blood stain on concrete can fade over time due to exposure to the elements, particularly sunlight and rain, but it might not completely disappear on its own. Sometimes, people resort to painting or resurfacing the concrete if the stain is in a conspicuous place and particularly bothersome.