What can I use to wash off dried blood stains

Everyone knows that blood stains on clothes or bedding, as well as some blood stains from poultry, are very difficult to deal with, especially over a long period of time, and dried blood stains are extremely difficult to deal with. It is recommended not to use hot water to clean, because the blood contains components such as plasma and protein, which become insoluble in water after drying. Similarly, blood stains will undergo chemical changes if exposed to the air for a long time, making them more difficult to handle and clean. This is why we say that old blood stains are difficult to wash off.

Question 1

1. Clothes, bed sheets, quilt covers, etc., stained with blood, must be washed immediately, otherwise the blood stains will be difficult to remove over time. And when cleaning blood stains, you cannot use hot water, only cold water.

I specially did the following experiment: take two pieces of white cloth and drop a few drops of fresh chicken blood on each of them. Soak a piece of white cloth in hot water and another piece of white cloth in cold water. After a while, take out the two pieces of white cloth and find that the bloodstains soaked in hot water have turned dark red, while the bloodstains soaked in cold water are still bright red, and the color has also become lighter. Take some soap and rub the blood stains on the two pieces of white cloth. Use the white cloth soaked in cold water to clean the blood stains thoroughly. However, blood stains soaked in hot water cannot be cleaned.

To explain:

The blood contains protein components such as plasma which can dissolve in water, but after being heated, they become insoluble in water. It is the same as the chicken blood, pig blood, or eggs we usually eat. After heating, it turns into a lump that is insoluble in water, which makes it naturally difficult to wash clean. By the same token, similar chemical changes will occur when blood stains are exposed to the air for a long time. This is why old blood stains are difficult to wash off.

Question 2

2. To wash blood stains, soak them in cold water first, then wash them with enzyme detergent. Or wash with soap or 10% potassium iodide solution; or use white radish juice or mashed carrots mixed with salt to remove blood stains on clothes; or use 10% tartaric acid solution to wipe the stained area, and then wash with cold water; using enzyme laundry detergent to remove blood stains is very effective.

Question 3

3. Old blood stains can be washed away with oxalic acid. You can also wash with lemon juice and salt water. (It's old.)

To explain: old bloodstains turn dark brown because the iron in the hemoglobin is oxidized in the air to form rust. Fruit juice also contains iron, which can form brown rust stains on clothes when it comes into contact with oxygen in the air. Therefore, stains caused by blood, juice and rust can be washed away with oxalic acid, which turns rust into a colorless substance that dissolves in water.

Question 4

4. Whether it is a new stain or an old stain, it can be cleaned by rubbing with sulfur soap.

Question 5

5. Blood stains on white clothes can be removed by mixing 1 part sodium thiosulfate and 50 parts water, diluting and dissolving the mixture and heating to 35°C. Then soak the white clothes until the blood color disappears and then wash with water. You can also soak the fabric in a 3% vinegar solution, leave it for 12 hours, and then rinse it with water. The effect is also very good.