Removing blood from a rug
Blood on a rug is one of the few stains with a hard chemical rule: never heat. Haemoglobin, the red component of blood, coagulates at warm temperatures and bonds permanently to the wool fibre. Once warm water has been applied, the stain is built in. Anyone who works cold removes it completely in most cases.
#Why cold water is non-negotiable
Blood consists largely of water, proteins and haemoglobin. While fresh, the proteins are water-soluble and can be washed out without trouble. As soon as they are exposed to temperatures above about 35 degrees Celsius, coagulation begins. The proteins clump together and bond permanently to whatever they touch. In a wool fibre, that means: no longer removable.
The rule for any blood stain, whether human or from an injured pet, is: cold water, cool cloth, no warmth. Even trying to wash the stain out faster with warm water produces the opposite result.
Fresh blood stains can be removed without residue in 95 percent of cases, provided the heat rule is observed.
#Immediate action on fresh blood
Blot up the excess blood immediately with a dry white cloth. Blot, do not rub. Several times with a fresh side of the cloth, from the outside in.
Then cold water, ideally straight from the tap. Soak a second cloth in cold water, wring it out and dab the spot. Change the cloth often as soon as it picks up colour.
Alternatively, you can wrap ice cubes in a cloth and run them over the spot. The cold prevents further coagulation and loosens residual proteins.
Repeat the process until the cloth no longer picks up colour. With a fresh stain this is usually the case after only a few minutes.
Important: salt water is optional but effective. One teaspoon of salt in 250 ml of cold water. The saline solution pulls proteins out of the fibre and speeds up the cleaning.
#Step by step: dried blood stain
Step 1: Carefully run a blunt brush over the dried crust to remove loose remains. Do not damage the pile.
Step 2: For wool rugs, prepare a solution of cold water and a few drops of wool detergent. Dip the cloth, wring it out well, keep the spot damp for 10 minutes without soaking it.
Step 3: Use an enzyme-based stain remover. These cleaners contain proteases, enzymes that break proteins down. They are available in pet shops or pharmacies. Apply according to the manufacturer's instructions, always with cold water.
Step 4: On synthetic rugs (polypropylene, polyester) a 3 percent hydrogen peroxide solution from the pharmacy helps. Never use it on wool or silk, where it leads to visible bleaching.
Step 5: Follow up with clear cold water so that no detergent residue stays in the pile.
Step 6: Weigh down the spot with dry cloths and let it dry flat. Never use a hairdryer.
#Material-specific notes
Wool: cold water, wool detergent, enzyme cleaner. No bleach, no hydrogen peroxide. Lanolin protects the fibre, but it can be washed out by aggressive agents.
Silk: no water at all, neither warm nor cold. Silk reacts to moisture with water rings. Only blot the excess and call a specialist.
Cotton (kilim, dhurrie): cold water and mild detergent work well. With modern cotton rugs a machine wash on a cold programme is also conceivable, provided the piece is small enough and contains no hand-knotted knots.
Synthetic (polypropylene, polyester): the most uncomplicated. Cold water, mild soap, and hydrogen peroxide if needed. Pay attention to the backing, some synthetic rugs have a latex back that must not get too wet.
High pile: harder than short pile, because the blood reaches deeper into the pile. More blotting, more patience, more rounds.
#What not to do
Warm or hot water: the blood coagulates immediately. Never.
Hairdryer, iron, hot air: dry quickly and fix the stain permanently. Drying flat in the air is the only option.
Bleach on wool or silk: bleaches the fibre immediately and damages natural dyes.
Rubbing with pressure: destroys the fibre structure and drives the blood deeper in. Only blot, only with cold water.
Washing-up liquid with bleach or citrus extracts: leaves residues that attract dirt over time and can change colours. Mild wool detergent is the right choice.
Heavy-duty detergent with enzymes from the supermarket: some do contain suitable enzymes, but also bleach components and fragrances that are problematic on wool. Specialised stain removers are safer.
#When to call a professional
On silk rugs, immediately. Home treatment always makes matters worse here. Only blot the excess and cover the spot loosely with a dry cloth.
With large blood stains, for example after an injury. If the blood has reached the backing, surface blotting is not enough. Treat the surface with cold water, cover it and call a cleaner.
On old naturally-dyed pieces there is a risk that home remedies will attack the dyes. A professional wash is safer than experimental mixing of products.
A Hamburg rug wash costs 80 to 200 euros and removes even dried-in blood stains fully in 90 percent of cases, provided no warm water was used beforehand.