Why Most Stain Removers Ruin Your Wool Carpets

Most colour repair calls I receive start the same way: a harsh, oxidising spotter has damaged a fine rug or carpet. The owner did the right thing by acting fast. They just reached for the wrong bottle: most commercial spotters contain bleaching agents.

We usually call any colour loss on a carpet or rug a "bleach spot", whether it was caused by actual household bleach or any other bleaching agent. And there are a lot more of those in the cleaning cupboard than people think, including in your supermarket spotters.

What "bleach-based" really means

It isn't only the bottle of bleach under the sink. Many popular stain removers clean by oxidation: they release oxygen or chlorine to break stains apart. You'll see them sold as "oxy", "active oxygen" or "oxygen-powered".

The trouble is, this is a type of textile bleach, and oxidation can't tell the difference between a wine stain and the dye in your carpet. It breaks down both. In other words, it bleaches your carpets.

On nylon carpets, the colour of the spot tells the story

This is where it gets interesting, for a colour restorer anyway. On synthetic nylon carpets, different bleaching agents remove different colours, so the spot left behind tells me what happened, and what's missing:

• Household bleach (sodium hypochlorite) removes the blue and the red, leaving the yellow behind. That's why most chlorine bleach spots on nylon are yellow.
• Benzoyl peroxide, found in some wood fillers and acne creams, removes mainly the blue, leaving the dreaded pink spots.
• Strong acids, such as some descalers, can remove the red. The blue and yellow left behind make... green.

On wool and silk, it's a lot worse

• Chlorine bleach destroys the fibre. On wool and silk, household bleach doesn't just remove colour. It chemically burns and dissolves the fibre itself, leaving damaged, brittle or missing pile.
• Colour loss. Oxygen-based spotters strip dye, and the damage sometimes shows up hours or even days later, once the product has dried.
• Yellowing and weakening. Wool and silk are protein fibres, much like hair. Strong oxidisers and alkaline cleaners weaken them, so treated areas can yellow, feel harsh and wear faster. Silk is especially vulnerable.
• Colour bleeding. Most protein fibres like wool and silk are dyed with acid dyes. This means that the dyes need an acidic environment to keep their bond to the fibres. Alkaline products break this bond, so the dyes run into the surrounding areas, which is a real risk on Persian and Oriental rugs with strong contrasting colours.

How to check a label

UK cleaning products have to list certain ingredient types on the pack. Look for:

• "Oxygen-based bleaching agents"
• "Chlorine-based bleaching agents"
• Hydrogen peroxide or sodium percarbonate

If you see any of these, keep the product well away from wool and silk.

How to choose a stain remover for wool or silk carpets

Look for the WoolSafe Mark. WoolSafe is an international organisation that tests products to make sure they don't damage the colour or the fibres in rugs and carpets. Their laboratory tests are incredibly thorough and very few stain removers pass, so if you see the WoolSafe Approved stamp on a spotter, your carpets are in safe hands.

If the damage has already happened

• Stop. More product, or a different one, almost always makes it worse.
• Don't try to colour it in with felt tips, shoe polish or home dyes. I've seen it all, and it makes a professional repair much harder.
• Keep the bottle you used. Knowing the culprit helps work out what's been lost.
• Call a specialist. Where only the colour has gone, it can often be re-dyed to blend back in. Where the fibre itself has been chemically burnt, as with chlorine bleach on wool, the area may need reweaving or patching instead.

Why I made my own stain removers

After years of repairing this damage, I built Restorers Approved to finally offer a stain remover that's highly effective and genuinely safe for delicate fibres. Our Wool & Silk Stain Remover is WoolSafe Approved, bleach-free, mildly acidic to suit wool and silk, and fragrance-free, and it helps stop loosened dye from moving onto the surrounding fibres. And if that wasn't enough, it's a no-rinse formula: it dries to a crystallised powder that you simply vacuum away.

Not sure if your spotter is safe? Email me the label and I'll tell you.