{"id":"misun-patch-test-planner","version":"1.0.0","reviewedAt":"2026-08-15","jurisdiction":"Cosmetic products marketed at retail in the United States","whatItDoes":"Builds a dated schedule for a self-applied open application test across one or more new cosmetic products, stating the site, dose, frequency, duration, and post-application watch period for each, and marking every value as either a sourced rule or a scheduling choice we made.","whatItIsNot":"Not diagnostic patch testing, which a clinician performs with standardized allergens under occlusion. Not a diagnosis, an allergy prediction, a safety score, or a product rating.","basisDefinitions":{"sourced":"One of the documents in the source ledger states this value outright, or states the fact it rests on.","convention":"A scheduling choice we made, either inside a published range or where no source gives a figure. Shown to the reader as our choice rather than presented as evidence."},"constants":{"mlPerApplication":{"value":0.1,"unit":"mL","basis":"sourced","source":"roat-standardization","detail":"The standardized ROAT protocol dispenses 0.1 mL per application, suggested via a 1 cm3 syringe, over a marked area of about 4 cm2."},"quarterSpotAreaCm2":{"value":4.6,"unit":"cm2","basis":"sourced","sources":["aad-test-products","usc-coin-specs"],"detail":"The AAD instructs a quarter-sized spot. Computed from the statutory quarter dollar diameter of 0.955 inch, or 24.26 mm, that is about 4.6 cm2, which is effectively the 4 cm2 marked area used in the standardized protocol."},"applicationsPerDay":{"value":2,"basis":"sourced","sources":["hannuksela-1986","aad-test-products"],"detail":"Twice daily in both the original 1986 protocol and in the AAD's consumer guidance."}},"durationRules":[{"id":"leave-on-standard","days":7,"basis":"sourced","sources":["hannuksela-1986","aad-test-products"],"detail":"Seven days of twice-daily application is the original ROAT duration and the bottom of the seven to 10 day range the AAD gives."},{"id":"actives-and-acids","days":10,"basis":"convention","sources":["aad-test-products"],"detail":"Placing actives and exfoliating acids at the top of the published seven to 10 day range is our choice, on the reasoning that irritation from these classes often builds with repeated use."},{"id":"prior-reaction-floor","days":10,"basis":"convention","sources":["aad-test-products"],"detail":"When the reader reports having reacted to a cosmetic product before, every product in the plan is raised to the top of the published range. Our choice, not a documented rule."},{"id":"watch-tail","days":"2 by default, 4 after a reported prior reaction","basis":"convention","sources":["dermnet-open-application","roat-standardization"],"detail":"That a tail is needed is sourced: an allergic reaction is often only evident several days after application, and reactions in the standardized protocol usually appear at about day 4. The specific length of the tail is our choice."}],"siteRules":[{"id":"body-products","site":"Flexor forearm, near the crease of the elbow","basis":"sourced","sources":["hannuksela-1986","roat-standardization","aad-test-products"]},{"id":"face-products","site":"Side of the neck, or behind the ear","basis":"sourced","sources":["dermnet-open-application"]},{"id":"eye-area","site":"No self-applied site represents eyelid skin; the planner states this limit rather than offering a proxy","basis":"sourced","sources":["dermnet-open-application"]}],"exposureHandling":[{"id":"leave-on","detail":"Applied at normal use thickness and left in place until the next wash.","basis":"sourced","sources":["aad-test-products","hannuksela-1986"]},{"id":"rinse-off","detail":"Cleansers, body washes, and shampoos are left on for about one minute and then washed off, so the test reproduces real contact time rather than an exposure that never happens.","basis":"sourced","sources":["dermnet-open-application"]}],"concurrency":{"default":"One product at a time, so a reaction points at one product.","optional":"Up to two products at once on two clearly separated left and right sites.","cap":2,"basis":"convention","detail":"Both the default and the cap are our scheduling choices. The cap exists because attribution is the only thing this test provides that a general impression does not, and crowded sites destroy it."},"ordering":{"rule":"Products are queued by exposure and area, leave-on before rinse-off, largest and longest contact first.","basis":"convention","detail":"Our choice, so that a reader who abandons the schedule partway through has still cleared the products with the most contact."},"stopRule":{"basis":"sourced","sources":["hannuksela-1986","aad-test-products"],"detail":"The original protocol ran unless dermatitis appeared earlier, and the AAD instructs the reader to gently wash the product off as soon as possible and not use it again. The planner surfaces this as a stop condition rather than a step to complete."},"productClasses":[{"id":"leave-on-moisturizer","label":"Moisturizer, balm, cream, or facial oil","exposure":"leave-on","testDays":7,"durationBasis":"sourced","priority":10,"sources":["hannuksela-1986","aad-test-products"]},{"id":"sunscreen","label":"Sunscreen","exposure":"leave-on","testDays":7,"durationBasis":"sourced","priority":20,"sources":["hannuksela-1986","aad-test-products"]},{"id":"serum-active","label":"Serum or treatment with an active","exposure":"leave-on","testDays":10,"durationBasis":"convention","priority":30,"sources":["aad-test-products"]},{"id":"exfoliating-acid","label":"Exfoliating acid or peel","exposure":"leave-on","testDays":10,"durationBasis":"convention","priority":40,"sources":["aad-test-products","dermnet-open-application"]},{"id":"makeup-face","label":"Foundation, concealer, or other face makeup","exposure":"leave-on","testDays":7,"durationBasis":"sourced","priority":50,"sources":["hannuksela-1986","aad-test-products"]},{"id":"leave-in-hair","label":"Leave-in hair product","exposure":"leave-on","testDays":7,"durationBasis":"sourced","priority":60,"sources":["hannuksela-1986","dermnet-open-application"]},{"id":"deodorant","label":"Deodorant or antiperspirant","exposure":"leave-on","testDays":7,"durationBasis":"sourced","priority":70,"sources":["hannuksela-1986","aad-test-products"]},{"id":"cleanser","label":"Facial cleanser","exposure":"rinse-off","testDays":7,"durationBasis":"sourced","priority":80,"sources":["dermnet-open-application"]},{"id":"body-wash-shampoo","label":"Body wash or shampoo","exposure":"rinse-off","testDays":7,"durationBasis":"sourced","priority":90,"sources":["dermnet-open-application"]}],"processing":{"location":"Browser","submittedToServer":false,"storedByPlanner":false},"excludedByDesign":["No diagnosis, allergy prediction, or personal suitability verdict","No product rating, safety score, or quality ranking, including of our own products","No claim that any product treats, prevents, or improves a skin condition","No invented durations, doses, or sites where no source gives one","No advice that overrides the directions on a product label or instructions from a clinician"],"sourceLedger":[{"key":"hannuksela-1986","title":"Hannuksela and Salo 1986, The repeated open application test (ROAT), Contact Dermatitis","url":"https://pubmed.ncbi.nlm.nih.gov/2941220/","supports":"The original ROAT protocol: substances applied twice daily for 7 days to the flexor aspect of the forearm near the cubital fossa, unless dermatitis appeared earlier. Of patients with a questionable patch test result, 44% were positive on ROAT."},{"key":"roat-standardization","title":"Practical suggestions to improve standardization of repeated open application testing (ROAT) for daily use products","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC9131969/","supports":"Quantities and geometry: 0.1 mL per application, a marked area of roughly 4 cm2 on the volar forearm, twice daily, for a minimum of one week up to four weeks, with positive reactions usually developing at about 4 days."},{"key":"aad-test-products","title":"American Academy of Dermatology, How to test skin care products","url":"https://www.aad.org/public/everyday-care/skin-care-secrets/prevent-skin-problems/test-skin-care-products","supports":"Apply the product to a test spot twice daily for seven to 10 days. Choose a quarter-sized spot where the product will not be rubbed or washed away, such as the underside of the arm or the bend of the elbow, using the normal amount and thickness. Wash the product off if a reaction appears."},{"key":"dermnet-open-application","title":"DermNet, Open application test","url":"https://dermnetnz.org/topics/open-application-test","supports":"Site options including the inner forearm, elbow crease, behind the ear and the side of the neck; an application area of about 5 cm by 5 cm; washing cleansers and shampoos off after about one minute; and the observation that immediate stinging is usually irritation while an allergic reaction is often only evident several days after application."},{"key":"fda-hypoallergenic","title":"US Food and Drug Administration, Hypoallergenic Cosmetics","url":"https://www.fda.gov/cosmetics/cosmetics-labeling-claims/hypoallergenic-cosmetics","supports":"There are no Federal standards or definitions that govern the use of the term hypoallergenic, and the FDA states it knows of no scientific studies showing that products making the claim cause fewer adverse reactions than conventional products."},{"key":"usc-coin-specs","title":"31 U.S.C. 5112, Denominations, specifications, and design of coins","url":"https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title31-section5112&num=0&edition=prelim","supports":"The statute specifies a quarter dollar coin that is 0.955 inch in diameter, which is 24.26 mm, and that is what converts the AAD's quarter-sized spot into a measurable area."}],"correctionPolicy":"Review sources quarterly and correct confirmed protocol, dose, or citation errors in place with a new version and reviewedAt date."}