System 4 Scalp Treatment for colored hair

These describe what an ingredient is, not whether it is a problem. The stance marks above are the ratings; these are not.

• common irritantCOCAMIDOPROPYL BETAINE, PROPYLENE GLYCOL

  • COCAMIDOPROPYL BETAINE: A mild cleansing agent, but a recurring patch-test finding, usually traced to leftovers from how it is made. American Contact Dermatitis Society, Allergen of the Year 2004 (Fowler JF Jr, Dermatitis 2004;15(1):3-4).
  • PROPYLENE GLYCOL: A solvent that shows up in patch-test clinics, more often as irritation than as allergy. American Contact Dermatitis Society, Allergen of the Year 2018 (Jacob SE, Scheman A, McGowan MA, Dermatitis 2018;29(1):3-5).

• fragrance materialBENZYL ALCOHOL, MENTHA PIPERITA OIL, MENTHOL, LIMONENE

  • BENZYL ALCOHOL: Used both as a fragrance component and as a preservative; the EU names it either way. EU Regulation (EC) 1223/2009, Annex III entry 45: a fragrance substance whose presence must be indicated in the list of ingredients above 0,001% in leave-on and 0,01% in rinse-off products, because of established contact-allergy risk. That entry carries transition footnote (38), which is footnote (37) plus a condition: stock that does not comply may still be made available until 31 July 2028 only "provided that they comply with the restrictions applicable on 15 August 2023", and only if it was lawfully placed on the Union market before the 31 July 2026 cut-off. Entry 45 covers its non-preservative use; it is separately an allowed preservative at Annex V entry 34.
  • MENTHA PIPERITA OIL: A cooling essential oil the EU names on its own account as a fragrance substance to be declared on the label. EU Regulation (EC) 1223/2009, Annex III entry 361, inserted by Commission Regulation (EU) 2023/1545: a fragrance substance whose presence must be indicated in the list of ingredients above 0,001% in leave-on and 0,01% in rinse-off products. It is declarable in its OWN right, not by way of any component it carries. The name to look for on a label is "Mentha Piperita Oil". The duty applies now. Transition footnote (40) lets stock that does not comply, lawfully placed on the Union market before the 31 July 2026 cut-off, be made available until 31 July 2028.
  • MENTHOL: The cooling component of mint oils, named by the EU as a fragrance substance to be declared on the label. EU Regulation (EC) 1223/2009, Annex III entry 338, inserted by Commission Regulation (EU) 2023/1545: a fragrance substance whose presence must be indicated in the list of ingredients above 0,001% in leave-on and 0,01% in rinse-off products. It is declarable in its OWN right, not by way of any component it carries. The name to look for on a label is "Menthol". The duty applies now. Transition footnote (40) lets stock that does not comply, lawfully placed on the Union market before the 31 July 2026 cut-off, be made available until 31 July 2028.
  • LIMONENE: A citrus-smelling fragrance component named separately on the label; the one name covers three related isomers. EU Regulation (EC) 1223/2009, Annex III entry 88: a fragrance substance whose presence must be indicated in the list of ingredients above 0,001% in leave-on and 0,01% in rinse-off products, because of established contact-allergy risk. That entry carries transition footnote (37): stock that does not comply, lawfully placed on the Union market before the 31 July 2026 cut-off, may still be made available until 31 July 2028. It is marked on the racemic dl-limonene/Dipentene line and the (S)-(l-limonene) line, but NOT the (R)-p-mentha-1,8-diene (d-limonene) line, CAS 5989-27-5, whose duty was already running as entry 88 before Commission Regulation (EU) 2023/1545 and so needed no transition. All three isomers are declared under the single glossary name "Limonene", so that name on a label does not identify which of them is present.

• undeclared fragrance blendFRAGRANCE/PARFUM

  • FRAGRANCE/PARFUM: A blend the label does not itemize, so what is in it cannot be read from the ingredient list. EU Regulation (EC) 1223/2009 permits the collective term "parfum"; the SCCS Opinion on Fragrance Allergens (SCCS/1459/11) reviews the contact-allergy evidence for the substances it can contain.

• soothingNIACINAMIDE

  • NIACINAMIDE: A vitamin B3 form that supports the skin barrier and has anti-inflammatory activity; it turns up in products aimed at acne, rosacea and eczema. Camillo L, Zavattaro E, Savoia P, "Nicotinamide: A Multifaceted Molecule in Skin Health and Beyond", Medicina (Kaunas) 2025;61(2):254, DOI 10.3390/medicina61020254, PMID 40005371, open access: it "is extensively used in ... the treatment of dermatological conditions such as blistering diseases, atopic dermatitis, rosacea, and acne vulgaris", and contributes to reducing inflammation. On the acne evidence specifically: Liu H, Yu H, Xia J, Liu L, Liu GJ, Sang H, Peinemann F, "Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha-hydroxy acid) for acne", Cochrane Database Syst Rev 2020;5:CD011368, DOI 10.1002/14651858.CD011368.pub2, PMID 32356369, records "low-quality evidence" for every nicotinamide comparison it could pool, and none of its four nicotinamide studies measured the physician global assessment at all.