C: Vitality

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

• commonly dryingEthanol, Witch Hazel Extract

  • Ethanol: 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.
  • Witch Hazel Extract: A tannin-rich astringent; the distillate sold under this name usually carries added alcohol, which is where the dry finish comes from. United States Pharmacopeia monograph "Witch Hazel", USP-NF version 02_01, DOI 10.31003/USPNF_M89070_02_01. The public DOI landing page carries a 2018 copyright and shows the definition, "Witch Hazel is a clear, colorless distillate prepared from recently cut and partially dried dormant twigs of Hamamelis virginiana L."; the specification, a distillate to which "150 mL of alcohol" is added per 850 mL at 14,0% to 15,0% ethanol, sits behind the USP subscription paywall. The monograph governs the pharmacopoeial article, not every product that prints this INCI name.

• exfoliating acidLactic Acid, Glycolic Acid

  • Lactic Acid: An alpha hydroxy acid that loosens surface skin cells; it also makes skin more sun-sensitive while you use it. FDA, "Guidance for Industry: Labeling for Topically Applied Cosmetic Products Containing Alpha Hydroxy Acids as Ingredients" (announced at 70 FR 1721, 10 January 2005; FDA web pages title it "Labeling for Cosmetics Containing Alpha Hydroxy Acids"), which names this acid and recommends the statement "Sunburn Alert: This product contains an alpha hydroxy acid (AHA) that may increase your skin's sensitivity to the sun and particularly the possibility of sunburn."
  • Glycolic Acid: An alpha hydroxy acid that loosens surface skin cells; it also makes skin more sun-sensitive while you use it. FDA, "Guidance for Industry: Labeling for Topically Applied Cosmetic Products Containing Alpha Hydroxy Acids as Ingredients" (announced at 70 FR 1721, 10 January 2005; FDA web pages title it "Labeling for Cosmetics Containing Alpha Hydroxy Acids"), which names this acid and recommends the statement "Sunburn Alert: This product contains an alpha hydroxy acid (AHA) that may increase your skin's sensitivity to the sun and particularly the possibility of sunburn."