At a glance
| Chemical family | Anthraquinone disperse dye — textile colorant for polyester and synthetic fibres (CI 64500) |
| CAS number | 2475-45-8 |
| Classification | IARC Group 2B (possibly carcinogenic to humans, Monographs Vol. 48, 1990). The most common textile dye allergen. EU CLP Carc. 2, Skin Sens. 1. Restricted under OEKO-TEX Standard 100 |
| Where you encounter it | Polyester fabric (bedding, sleepwear, athletic wear, uniforms); acetate and nylon fabrics; some cosmetics (banned in EU cosmetics). Direct skin contact with dyed textiles |
| Sleep micro-environment relevance | Found in polyester bedding sheets, pillowcases, and sleepwear. The most common cause of textile dye contact dermatitis. 6-8 hours of direct skin contact during sleep maximises exposure |
Regulatory & certification status
| European Union | Banned in cosmetics (Cosmetics Regulation Annex II). CLP Carc. 2 (H351), Skin Sens. 1 (H317). Not specifically restricted in textiles under REACH, but restricted under OEKO-TEX Standard 100 (voluntary certification). Regulatory |
| United States | Not restricted in textiles. FDA prohibits in cosmetics applied to the eye area. No federal textile dye regulation. Regulatory |
| Canada | Not specifically restricted in textiles. Cosmetic Ingredient Hotlist restricts some dyes. Regulatory |
| International | IARC Group 2B (Monographs Vol. 48, 1990). OEKO-TEX Standard 100 restricts Disperse Blue 1 in certified textiles. The most common textile dye allergen in patch testing worldwide. Regulatory |
What it is
Disperse Blue 1 is an aminoanthraquinone dye used to colour polyester and other hydrophobic synthetic fibres. Disperse dyes are applied to polyester at high temperature and pressure — they dissolve into the fibre rather than bonding to it chemically. This means disperse dyes can migrate back out of the fibre during wear, washing, and sweating, transferring to the skin. IARC evaluated Disperse Blue 1 in 1990 and classified it as Group 2B based on limited evidence of carcinogenicity in humans and sufficient evidence in animals. It is also the most prevalent textile dye allergen — Disperse Blue 1, along with Disperse Blue 106 and Disperse Blue 124, accounts for the majority of positive patch test reactions to textile dyes in dermatology clinics. The EU has banned Disperse Blue 1 in cosmetics and it is restricted under OEKO-TEX Standard 100.
Where it shows up in bedding
Disperse Blue 1 is found in blue, navy, purple, and dark-coloured polyester bedding — sheets, pillowcases, duvet covers, and pillow protectors made from polyester or polyester blends. It is also present in dyed polyester sleepwear. The dye migrates from the fabric to the skin during sleep, especially when the fabric is warm and moist from body heat and perspiration. For Disperse Blue 1-sensitised individuals, this overnight exposure can cause persistent contact dermatitis at contact sites — typically the trunk, limbs, and face where dyed bedding or sleepwear contacts skin. The clinical pattern of dermatitis — matching clothing or bedding contact lines — provides the diagnostic clue. Switching to undyed (white) cotton or certified dye-free polyester bedding eliminates the exposure.
Citations
- IARC (1990). Disperse Blue 1. IARC Monographs Vol. 48. Source Peer-reviewed
- Svedman, C. et al. (2014). Textile Contact Dermatitis: How Exposures and Sensitization Patterns Have Changed. Contact Dermatitis, 71(5): 264-279. Source Peer-reviewed
- OEKO-TEX. Standard 100 — Testing for harmful substances. Source Industry
Frequently asked questions
Can my polyester sheets cause a skin rash?
If you are allergic to Disperse Blue 1 or other disperse dyes, dyed polyester sheets can cause contact dermatitis — a red, itchy rash at the areas where the fabric contacts your skin. The dye migrates from the polyester to your skin during sleep, especially when warm and moist. If you suspect textile dye allergy, a dermatologist can confirm with patch testing. Switching to white cotton or undyed sheets eliminates the exposure.
Why are disperse dyes allergens?
Disperse dyes dissolve into polyester fibres during dyeing but can migrate back out during wear. When they contact the skin, they can act as haptens — small molecules that bind to skin proteins and trigger an immune response in sensitised individuals. Disperse Blue 1 is the most common textile dye allergen, but the related dyes Disperse Blue 106 and 124 also frequently cause reactions.
Related compounds
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Last reviewed 2026-07-08. If you find a factual error, contact us.