Manufacturer · Fashion & Home Accessories
There are three bleaching symbols on care labels, and all of them are triangles. An empty triangle allows any bleaching agent, including chlorine bleach. A triangle with two diagonal lines inside allows only oxygen (non-chlorine) bleach. A solid crossed-out triangle means that the item must not be bleached.
Bleaching symbols according to ISO 3758
The triangle is the second symbol in the row on a care label, after the washtub. It refers to bleaching agents added during or before washing, as well as to stain removers based on bleaching substances.
| Symbol | Meaning | Typical items |
|---|---|---|
| Empty triangle | Any bleaching agent is allowed – chlorine and oxygen | White cotton and linen items: sheets, towels, medical clothing |
| Triangle with two diagonal lines | Only oxygen / non-chlorine bleach is allowed | Coloured cotton garments, blended fabrics |
| Crossed-out solid triangle | Do not bleach | Wool, silk, elastane, most coloured and dark items |
If you see a triangle with the letters "Cl" on older labels, it means that chlorine bleach is permitted. In the current version of the standard, this variant has been replaced by the empty triangle.
Chlorine versus oxygen bleach
Chlorine bleach
Chlorine bleach (based on sodium hypochlorite) is a strong oxidising agent. It bleaches and disinfects, but it breaks down protein fibres such as wool and silk, weakens elastane and can strip the colour from dyed fabrics. It is therefore only allowed on items that are white and can withstand aggressive treatment.
Oxygen bleach
Oxygen bleaches (based on percarbonate or hydrogen peroxide) are gentler. Most washing powders already contain them. They are suitable for coloured cotton and blended fabrics, but even then it is a good idea to test colour fastness on a hidden area.
Why manufacturers often prohibit bleaching
If you look at the labels of the clothes in your wardrobe, you will see that the crossed-out triangle is the most common bleaching symbol. There are several reasons:
- Most garments are coloured and their dyes have not been tested against bleaching agents.
- The composition contains elastane, wool or silk, which are damaged by chlorine.
- The item has a print, embroidery or appliqués whose colours may fade.
- Accessories – metal buttons, eyelets and zips – can darken or rust on contact with chlorine.
The prohibition is also a protective measure for the brand: it reduces the risk of complaints if the customer uses a strong product.
Practical tips for consumers
- Never mix chlorine bleach with other products, especially those based on ammonia or acids.
- Do not pour bleach directly onto the garment – dilute it in the water.
- If the label shows two diagonal lines, use only products marked "chlorine-free" or "oxygen".
- For stains on an item with a crossed-out triangle, look for an enzyme-based product or professional cleaning.
Bleaching symbols when preparing the label
For the brand, the decision depends on testing. If the item is white, made of 100% cotton or linen and the accessories are resistant, the empty triangle can be used. For coloured cotton items, the triangle with two lines is the most common choice. For anything with elastane, wool, viscose or delicate decorations – the crossed-out triangle.
The symbol is printed in the row of symbols on the care and composition label, usually in black, at a size that stays legible after washing. For the main brand label, you can choose a printed label in the same colour, and you will find the full range of options in our labels category.
Bleaching and garment accessories
It is often forgotten that bleach affects more than the fabric. Metal buttons, eyelets, rivets and metal zips can darken, lose their plating or leave rust stains on the fabric if they come into contact with chlorine. Plastic buttons usually withstand it, but dyed ones may fade. Embroidery threads and textile labels also have their own colour fastness. So if the item has coloured or metal details, the bleaching symbol must take them into account too. Garment technologists often carry out the test on the finished sample rather than just on a piece of fabric, precisely to see how all the components react together.
Bleaching, brightening and optical brighteners
The bleaching symbol should not be confused with optical brighteners, which are found in many washing powders. They do not remove stains; they reflect light and make whites look brighter. On pastel and coloured fabrics they can change the shade. That is why detergents for coloured laundry are recommended for coloured garments, even if the label allows oxygen bleach.
How the bleaching symbol combines with the others
The combination must be logical. An empty triangle rarely appears next to a washtub with 30 °C and two bars – if the item is that delicate, it is unlikely to tolerate chlorine. Conversely, white hospital clothing washed at 60 or 95 °C almost always allows bleaching. Checking for such inconsistencies before printing saves you from reprinting the whole batch of labels.
Care labels from Polkom
Polkom is a manufacturer of labels and garment accessories based in Sofia with over 30 years of experience. We print the bleaching symbols and the other care instructions together with your composition and logo, make a sample and deliver across the EU. Send us your details via our contact page to request a quote.
