What do the Clean, Low, Watch and Swap levels mean?

They are cut from a continuous concern level the app computes from the sourced claims that the chosen evidence lens shows: each claim counts its concern class, tier weight, confidence and dose relevance, combined worst-first with a decay so one serious finding outweighs many small ones, then scaled by how much of the substance reaches you in this use. Clean is below 0.35, Low below 1.1, Watch below 2.0 and Swap above that, on a 0 to 3 scale.

Is Methylisothiazolinone safe on skin (rinsed off)?

Q: Is methylisothiazolinone safe on skin (rinsed off)?

Under the app's default Cautious lens, methylisothiazolinone on skin (rinsed off) rates Low: a little concern, nothing the app would ask you to swap. 2 sourced concerns count (restricted, consensus tier; irritant · allergen, consensus tier). This is research with sources, not medical advice.

Personal care1 use researched2 sourced claims

Where it turns up: preservative in rinse-off products. Detox My Life researched methylisothiazolinone under one use, because the same substance means something different in each use. Every claim below carries its evidence tier, how sure the research is that it applies here, and the sources it cites. The level is computed by the app's own deterministic engine, so the page says exactly what the app would.

Level by use and lens

Use	Mainstream	Cautious (default)	Based	Concerns · favour · fringe
On skin, rinsed off	Low	Low	Low	2 · 0

Mainstream shows consensus claims only; Cautious adds emerging research; Based adds fringe claims, labelled as such. The last column counts, under Cautious, the sourced concerns, the findings in its favour and the fringe claims Based would add.

Safer swaps: the app's swap catalog has no entry tied to this ingredient yet. When you scan a product that contains it, the app suggests cleaner alternative types for that product; the swap categories list what the catalog covers today.

On skin, rinsed off Low

Under the default Cautious lens methylisothiazolinone on skin (rinsed off) rates Low: a little concern, nothing the app would ask you to swap. Mainstream (consensus only) rates it Low; Based (adds the fringe) rates it Low. Researched 2026-09-03.

Sourced concerns (2)

ConsensusRestrictedconfidence 50%

The European Union restricts the concentration of methylisothiazolinone in rinse-off cosmetic products to a maximum of 15 ppm (0.0015%) due to its potential to cause allergic contact dermatitis.

Why here: This regulatory restriction specifically applies to rinse-off dermal products to mitigate the risk of skin sensitization and allergic reactions during normal use by limiting exposure levels.
What would have to be true: Dermal exposure to rinse-off cosmetic products containing methylisothiazolinone at concentrations exceeding 15 ppm is prohibited by EU regulation.
The other side: None, this is a regulatory action based on scientific opinions.

Sources the engine cites:

Methylisothiazolinone in cosmetic products — biorius.com (2017) · regulator or public body
Safety-in-use of methylisothiazolinone in cosmetic products — gov.uk (2015) · regulator or public body
4 web articles (cosmeticsandtoiletries.com, mi-free.com, ireadlabelsforyou.com, …), linked in the app.

ConsensusIrritant · allergenconfidence 50%

Methylisothiazolinone is a potent skin sensitizer and can cause allergic contact dermatitis in individuals exposed to rinse-off cosmetic products.

Why here: Even with short contact times, methylisothiazolinone in rinse-off products can penetrate the skin, especially when detergents are present, leading to sensitization or elicitation of allergic reactions.
What would have to be true: Dermal exposure to rinse-off cosmetic products containing methylisothiazolinone, particularly at concentrations above 15 ppm, has been shown to elicit reactions in sensitized individuals.
The other side: The European Scientific Committee on Consumer Safety (SCCS) considers a concentration of 15 ppm (0.0015%) safe for the consumer from the point of view of induction of contact allergy in rinse-off products, but not for elicitation or induction at 50 ppm or 100 ppm.

Sources the engine cites:

Methylisothiazolinone in rinse-off products causes allergic contact dermatitis: a repeated open-application study — nih.gov (2015) · regulator or public body
2 web articles (sincereskincare.com, webmd.com), linked in the app.

Not researched here

The engine has no dossier for methylisothiazolinone when cooked with heat, in cold food, as a finishing ingredient, in heated food packaging or other uses. The app researches an ingredient for the use it infers from your product, so a scan fills these in; this page only shows what has already been researched and source-verified.

This is research, not medical advice. Detox My Life shows sourced claims sorted by evidence tier. It does not diagnose, treat, or tell you to start or stop anything. Talk to a qualified professional about your health.

Scan your own. The app reads any product label with your camera, works out how you are about to use it, and researches every ingredient for that use with live sources. Every scan adds to a Detox Score for your home, where 50 is a typical home in your region, and a plan of next swaps.

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