Shea butter hair mask

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

• comedogenic in testingIsopropyl Myristate

  • Isopropyl Myristate: A light emollient, and the ester the rabbit-ear literature names first. Fulton JE Jr, Pay SR, Fulton JE 3rd, "Comedogenicity of current therapeutic products, cosmetics, and ingredients in the rabbit ear", J Am Acad Dermatol 1984;10(1):96-105, PMID 6229554. The openly readable abstract names this ingredient among its "ingredient offenders", in prose and without a numeric rating: "Ingredient offenders include isopropyl myristate and its analogs, such as isopropyl palmitate, isopropyl isostearate, butyl stearate, isostearyl neopentanoate, myristyl myristate..." The rabbit-ear assay rates raw ingredients and does not predict how a finished formula behaves on human skin.

• common irritantPropylene Glycol, DMDM Hydantoin

  • 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).
  • DMDM Hydantoin: A preservative the FDA lists as a formaldehyde releaser, which is why formaldehyde-reactive skin can notice it. How much reaches the skin depends on the whole formula, not on this name alone. EU Regulation (EC) 1223/2009, Annex V entry 33, permits DMDM hydantoin as a preservative up to 0,6%. The FDA names it among the "formaldehyde and formaldehyde releasing ingredients" on its Allergens in Cosmetics page (content current 25 February 2022). SCCS Scientific Advice SCCS/1632/21, on the threshold for the "contains formaldehyde" warning, describes a study in which a moisturiser spiked to the 0,6% Annex V maximum released at least 40 ppm formaldehyde. Annex V preamble point 2, as amended by Commission Regulation (EU) 2022/1181, requires the warning "releases formaldehyde" on any product whose total released formaldehyde exceeds 0,001% (10 ppm). That Regulation states the sensitisation ground itself, so the chain is drawn by the regulator and not by us: recital (2) names the class, "Certain of those preservatives are gradually releasing formaldehyde in order to fulfil a preserving function in the final cosmetic product (so called formaldehyde releasers)", and recital (3) gives the purpose of the warning, "In order to inform consumers sensitised to formaldehyde about the presence of formaldehyde that may trigger an allergic reaction". Recital (1) records that formaldehyde is classified a skin sensitizer (Category 1) in Part 3 of Annex VI to Regulation (EC) 1272/2008.

• fragrance materialLinalool, Butylphenyl Methylpropional, Benzyl Salicylate, Hydroxycitronellal

  • 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.
  • 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.
  • 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.
  • Hydroxycitronellal: A lily-like fragrance component named separately on the label. EU Regulation (EC) 1223/2009, Annex III entry 72: 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 blendParfum

  • 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.