Nail Hardener, Bamboo

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

• commonly dryingALCOHOL, ISOPROPYL ALCOHOL

  • ALCOHOL: A fast-evaporating solvent that leaves a dry finish. International Chemical Safety Card ICSC 0044, Ethanol (anhydrous), prepared by an international group of experts for the ILO and WHO: "The substance defats the skin, which may cause dryness or cracking." Bommannan et al., as reported by Lachenmeier DW, "Safety evaluation of topical applications of ethanol on the skin and inside the oral cavity", J Occup Med Toxicol 2008;3:26, DOI 10.1186/1745-6673-3-26, open access, reference 82: "Bommannan et al. found in vivo in humans that ethanol enters the skin and removes measurable quantities of the lipid barrier material from the stratum corneum." Both describe stronger exposures than a cosmetic formula.
  • ISOPROPYL ALCOHOL: A fast-evaporating solvent with a drying finish, common in toners and hand products. International Chemical Safety Card ICSC 0554, Isopropyl alcohol, prepared by an international group of experts for the ILO and WHO: "Repeated or prolonged contact with skin may cause dryness and cracking." It describes a stronger exposure than a cosmetic formula.

• common irritantPROPYLENE GLYCOL

  • 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).

• retinoidRETINYL PALMITATE

  • RETINYL PALMITATE: A gentler vitamin A ester that the skin converts to retinol. SCCS Opinion on Vitamin A (Retinol, Retinyl Acetate, Retinyl Palmitate), SCCS/1576/16, which assesses retinyl palmitate by name; EU Regulation (EC) 1223/2009 Annex III entry 376 covers it in the same group as retinol.

• 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."