One Hair Shampoo

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

• common irritantSodium Lauryl Sulfate, Cocamidopropyl Betaine, Methylchloroisothiazolinone, Methylisothiazolinone

  • Sodium Lauryl Sulfate: A strong cleansing agent used as the reference irritant in skin-irritation testing. OECD Test Guideline 439 (in vitro skin irritation, reconstructed human epidermis), paragraph 24: "The suggested PC is 5% aqueous SDS", sodium dodecyl sulphate, the same substance as sodium lauryl sulfate, CAS 151-21-3.
  • 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).
  • Methylchloroisothiazolinone: A preservative restricted to rinse-off products in the EU because of contact-allergy reports. EU Regulation (EC) 1223/2009, Annex V entry 39 (rinse-off only, 0,0015% of a 3:1 mixture with methylisothiazolinone). The reason is in Commission Regulation (EU) No 1003/2014, recital 3, quoted rather than summarised: "The SCCS concluded that the mixture of Methylchloroisothiazolinone (and) Methylisothiazolinone in a ratio of 3:1 does not pose a risk to the health of the consumer when used as a preservative up to a maximum authorised concentration of 0,0015 % in rinse-off cosmetic products, apart from its skin sensitising potential. The SCCS indicated that induction and elicitation would be less likely in a rinse-off product than when the same concentration is present in a leave-on product." SCCS/1238/09 concludes it "is well recognised as an important skin sensitiser at current conditions of use".
  • Methylisothiazolinone: A preservative that patch-test clinics see reactions to often enough that the EU banned it from leave-on products. American Contact Dermatitis Society, Allergen of the Year 2013 (Castanedo-Tardana MP, Zug KA, Dermatitis 2013;24(1):2-6); SCCS Opinion on Methylisothiazolinone (P94), Submission II, SENSITISATION ONLY (SCCS/1521/13, revision of 27 March 2014); banned in leave-on cosmetics by Commission Regulation (EU) 2016/1198, which recites the need to address "the increased incidence of allergies induced by methylisothiazolinone".

• fragrance materialBenzyl Alcohol, Coumarin

  • 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.
  • Coumarin: A sweet hay-scented fragrance component named separately on the label. EU Regulation (EC) 1223/2009, Annex III entry 77: 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.

• undeclared fragrance blendFragrance

  • Fragrance: 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.

• humectantPanthenol, Glycerin

  • Panthenol: A provitamin B5 humectant used in products aimed at irritated and healing skin. On the humectant half: Ferreira VTP, Silva GC, Martin AA, Maia Campos PMBG, "Topical dexpanthenol effects on physiological parameters of the stratum corneum by Confocal Raman Microspectroscopy", Skin Res Technol 2023;29(9):e13317, DOI 10.1111/srt.13317, PMID 37753694, PMCID PMC10504581, open access, Introduction: "As a humectant, it has been shown to retain water more efficiently than other humectants during the last stages of dehydration..." On the soothing half, which that paper does NOT support: Cho YS, Kim HO, Woo SM, Lee DH, "Use of Dexpanthenol for Atopic Dermatitis—Benefits and Recommendations Based on Current Evidence", J Clin Med 2022;11(14):3943, DOI 10.3390/jcm11143943, PMID 35887707, open access, section 3.5: "To facilitate wound healing, dexpanthenol reduces inflammation, and promotes cell proliferation and epithelial remodeling."
  • Glycerin: A humectant, and one of the two ingredients a comparison of moisturiser components found made a significant difference to skin hydration. FDA OTC skin protectant monograph, 21 CFR 347.10(h), lists glycerin as a skin protectant at 20 to 45%. On the humectant half: Jeong CB, Han JY, Cho JC, Suh KD, Nam GW, "Analysis of electrical property changes of skin by oil-in-water emulsion components", Int J Cosmet Sci 2013;35(4):402-410, DOI 10.1111/ics.12059, PMID 23621673, found that "glycerine and urea showed significant skin hydration effects compared with other humectants".

• soothingPanthenol

  • Panthenol: A provitamin B5 humectant used in products aimed at irritated and healing skin. On the humectant half: Ferreira VTP, Silva GC, Martin AA, Maia Campos PMBG, "Topical dexpanthenol effects on physiological parameters of the stratum corneum by Confocal Raman Microspectroscopy", Skin Res Technol 2023;29(9):e13317, DOI 10.1111/srt.13317, PMID 37753694, PMCID PMC10504581, open access, Introduction: "As a humectant, it has been shown to retain water more efficiently than other humectants during the last stages of dehydration..." On the soothing half, which that paper does NOT support: Cho YS, Kim HO, Woo SM, Lee DH, "Use of Dexpanthenol for Atopic Dermatitis—Benefits and Recommendations Based on Current Evidence", J Clin Med 2022;11(14):3943, DOI 10.3390/jcm11143943, PMID 35887707, open access, section 3.5: "To facilitate wound healing, dexpanthenol reduces inflammation, and promotes cell proliferation and epithelial remodeling."