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 P-Phenylenediamine safe on skin (rinsed off)?

Q: Is p-phenylenediamine safe on skin (rinsed off)?

Under the app's default Cautious lens, p-phenylenediamine on skin (rinsed off) rates Low: a little concern, nothing the app would ask you to swap. 2 sourced concerns count (irritant · allergen, consensus tier; environmental, emerging tier). 1 finding count in its favour. This is research with sources, not medical advice.

Personal care1 use researched3 sourced claims

Where it turns up: primary permanent hair dye ingredient. Detox My Life researched p-phenylenediamine 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 · 1

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 covers the products this turns up in: Hair dye. Alternatives are always types, never brands.

On skin, rinsed off Low

Under the default Cautious lens p-phenylenediamine 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)

ConsensusIrritant · allergenconfidence 90%

P-phenylenediamine (PPD) is a potent skin sensitizer that can cause allergic contact dermatitis, characterized by symptoms such as redness, swelling, blistering, and itching on the scalp, face, eyelids, and neck, when used in oxidative hair dyes.

Why here: PPD in hair dyes is applied to the scalp and hair, allowing for direct skin contact and subsequent sensitization before the product is rinsed off.
What would have to be true: Dermal contact with PPD-containing oxidative hair dyes during application, with reactions typically appearing 24-72 hours after exposure. The EU restricts PPD to a maximum on-head concentration of 2% after mixing.

Sources the engine cites:

Quantification of p-Phenylenediamine in Hair Dyes and Health Risk Implications in the UAE: Describing Discordances Between Regulations and Real-Life Practices - PMC — nih.gov (2024) · regulator or public body
Para-phenylenediamine allergy: current perspectives on diagnosis and management - PMC — nih.gov (2017) · regulator or public body
5 web articles (news-medical.net, doctorkatta.com, myhairdoctor.com, …), linked in the app.
4 community or commercial pages, not counted here.

EmergingEnvironmentalconfidence 80%

P-phenylenediamine (PPD) is very toxic to aquatic life, and its presence in rinse-off hair dye products means it can enter waterways and negatively impact aquatic ecosystems.

Why here: Hair dye products are designed to be rinsed off, leading to the discharge of PPD into wastewater systems.
What would have to be true: Discharge of rinse-off hair dye products containing PPD into wastewater.

Sources the engine cites (no regulator, review or study among them):

1 community or commercial page, not counted here.

In its favour (1)

EmergingClearedconfidence 80%

When p-phenylenediamine (PPD) reacts with hydrogen peroxide in oxidative hair dyes, it can form Bandrowski's base, a substance shown to be strongly mutagenic (DNA-altering) and possibly carcinogenic, though studies on cancer risk from personal hair dye use have conflicting results. The International Agency for Research on Cancer (IARC) classifies occupational exposure to hair dyes as "probably carcinogenic to humans" (Group 2A), but personal use as "not classifiable as to its carcinogenicity to humans" (Group 3).

Why here: The formation of these byproducts occurs on the hair and scalp during the dyeing process, which is a dermal rinse-off application, allowing for potential skin absorption of these substances.
What would have to be true: Dermal exposure to hair dye formulations containing PPD and hydrogen peroxide during the application and rinse-off process.
The other side: The U.S. Environmental Protection Agency (EPA) has not classified p-phenylenediamine with respect to carcinogenicity and states it is not carcinogenic by oral or dermal exposure.

Sources the engine cites:

p-Phenylenediamine 106-50-3 - epa nepis — epa.gov (2000) · regulator or public body
2 community or commercial pages, not counted here.

Not researched here

The engine has no dossier for p-phenylenediamine 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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