These describe what an ingredient is, not whether it is a problem. The stance marks above are the ratings; these are not.
common irritantPropylene Glycol, Methylchloroisothiazolinone, Methylisothiazolinone
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).
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".
EU Regulation (EC) 1223/2009, Annex III entry 67: 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.
Benzyl Salicylate: A faintly floral fragrance component named separately on the label. EU Regulation (EC) 1223/2009, Annex III entry 75: 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. The entry was replaced by Commission Regulation (EU) 2026/909 of 27 April 2026, which caps it per product type from 0,004% in oral products to 4% in fragrance products; under its footnote (**), products not complying may not be placed on the Union market from 1 January 2027, nor made available from 1 July 2028.
Butylphenyl Methylpropional: A lily-of-the-valley fragrance component the EU no longer permits in cosmetics. It was a declarable fragrance allergen at Annex III entry 83 of EU Regulation (EC) 1223/2009. Commission Regulation (EU) 2021/1902 deleted that entry and moved it to Annex II entry 1666 (2-(4-tert-butylbenzyl) propionaldehyde, CAS 80-54-6), prohibiting it in cosmetic products from 1 March 2022.
Linalool: A floral fragrance component named separately on the label. EU Regulation (EC) 1223/2009, Annex III entry 84: 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.
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
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
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."
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."
