Paul Mitchell Shampoo Three Chlorine Removing Cleanser

DESCRIPTION

What It Does: Provides the defining fresh citrus fragrance note alongside solvent and antimicrobial properties.

Why It's Used: The citrus industry's primary fragrance compound and the most abundant terpene in essential oils – limonene provides the clean, universally appealing fresh citrus scent character.

How It Works: D-limonene activates trpv1 mildly at high concentrations. antimicrobial via membrane disruption. solvent for oils and lipophilic compounds. cleaning via emulsification of lipid soils.

Typically Found In: Citrus-scented products,cleaning products,fragrance compounds

TECHNICAL DETAILS

Primary Category: Fragrance component – cyclic monoterpene

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.001%–3%

SOURCING & ETHICS

Vegan Status: Yes – from citrus peel essential oils

Halal Status: Yes

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Eu cosmetics regulation: declared fragrance allergen. oxidises to sensitising compounds (limonene hydroperoxides) on air exposure – use with antioxidant stabilisers. ifra guidelines apply.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Limonene's sensitisation risk arises not from limonene itself but from its autooxidation products (limonene-1,2-epoxide and limonene hydroperoxides) formed on air exposure. fresh limonene has low sensitisation potential, but air-oxidised limonene's hydroperoxide products are potent skin sensitisers. this explains why oxidation-stabilised formulations (with bht or other antioxidants) are required to manage limonene safety.

Last Verified: Cosing database,ifra standards,bråred christensson et al. limonene oxidation study

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides mineral ion delivery to skin, modulates formulation ionic strength for viscosity and stability optimisation, and supports skin enzyme activity through essential mineral cofactor supplementation.

Why It's Used: Mineral salts are essential formulation ph and ionic strength adjusters — magnesium sulfate specifically provides the mg²⁺ ions that activate transglutaminase crosslinking during sc cornification, supporting barrier formation.

How It Works: Ionic dissociation in aqueous formulation provides free ions that modulate polymer viscosity (ionic strength reduces charge-based thickener swelling), provide mineral nutrition to skin enzymes (ca²⁺ for transglutaminase, mg²⁺ for mgatp phosphotransferases), and adjust osmolality for skin-surface tonicity matching.

Typically Found In: All formulations,mineral skin care

TECHNICAL DETAILS

Primary Category: Active ingredient – mineral / metal active

Secondary Functions: Antimicrobial,sebum regulation,antioxidant enzyme cofactor

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.01%–5%

SOURCING & ETHICS

Vegan Status: Yes – mineral

Halal Status: Yes

Source Notes: Mineral/inorganic compound. cosmetic or pharmaceutical grade.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Non-irritating at recommended concentrations.

Safe for Sensitive Skin: Yes at recommended concentrations

SAFETY & COMPATIBILITY

Safety Profile: Excellent safety profile at cosmetic concentrations. ewg score: 1–2.

Works Well With: Niacinamide,salicylic acid,other actives

Avoid Combining With: No significant incompatibilities at standard concentrations

SCIENTIFIC NOTE

Mg²⁺ and ca²⁺ are essential cofactors for the sc cornification process — ca²⁺ specifically drives the ca²⁺ gradient across the epidermis (high in outer sc, low in basal layer) that regulates keratinocyte differentiation through ca²⁺-calmodulin signalling.

Last Verified: Cosing database,magnesium sulfate mineral salt formulation review

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Delivers characteristic cosmetic function at recommended use concentration.

Why It's Used: Selected for functional contribution and formulation compatibility supported by cosmetic science and regulatory safety data.

How It Works: Works through the mechanism of its molecular class as documented in peer-reviewed cosmetic literature.

Typically Found In: Skin care formulations

TECHNICAL DETAILS

Primary Category: Active ingredient – cosmetic active

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.1%–10%

SOURCING & ETHICS

Vegan Status: Conditional

Halal Status: Yes

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Good safety profile at recommended concentrations. ewg score: 1–2.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Methylchloroisothiazolinone has an established safety profile within the cosmetic regulatory framework at standard use concentrations.

Last Verified: Cosing database,methylchloroisothiazolinone technical literature

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides highly potent broad-spectrum preservation at very low concentrations in rinse-off formulations.

Why It's Used: Most potent cosmetic preservative — mit provides effective preservation at concentrations 10-100× lower than most other preservatives, enabling clean-label preservation at minimal ingredient load.

How It Works: Electrophilic isothiazolinone ring reacts with bacterial thiol enzymes (glutathione, coa-dependent enzymes) via michael addition for rapid kill. very potent — mic vs e. coli 0.06μg/ml (vs phenoxyethanol mic ~400μg/ml — 6000× more potent). rapidly biodegradable.

Typically Found In: Rinse-off shampoos,body washes,conditioners

TECHNICAL DETAILS

Primary Category: Functional ingredient – isothiazolinone preservative

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.0015%–0.0015% (max 15ppm eu rinse-off)

SOURCING & ETHICS

Vegan Status: Yes – synthetic

Halal Status: Yes

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Eu regulation 2014/1298: mit banned from leave-on products. max 15ppm in rinse-off only. contact sensitiser — causes occupational dermatitis epidemic in hairdressers and consumers. sccs noted no safe level for leave-on. 2016 eu restriction driven by major sensitisation epidemic.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Mit's sensitisation epidemic (2010-2015) is one of the most significant cosmetic safety events in modern dermatology: a dramatic increase in contact allergy patch test positive rates from <1% (2005) to 7% (2015) in the eu was directly traceable to the widespread introduction of mit in leave-on products. this epidemic prompted the fastest eu cosmetic regulatory action in history and demonstrates the critical importance of patch test surveillance in monitoring emerging cosmetic allergens.

Last Verified: Cosing database,eu regulation 2014/1298,yazar et al. mit sensitisation epidemic study

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides powerful cleansing and rich foam but with significant skin barrier disruption at typical concentrations.

Why It's Used: Despite its widespread use, sls is a known irritant and barrier disruptor – modern formulations are increasingly replacing sls with milder alternatives or reducing concentration and buffering with mild co-surfactants.

How It Works: Anionic sulfate headgroup binds to positively charged lysine/arginine residues in skin proteins (keratin, structural proteins) causing denaturation. also solubilizes stratum corneum lipids disrupting the barrier. 12-carbon chain provides optimal critical micelle concentration for cleansing.

Typically Found In: Shampoos,cleansers,toothpaste,foaming products

TECHNICAL DETAILS

Primary Category: Functional ingredient – primary anionic surfactant

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.5%–15%

SOURCING & ETHICS

Vegan Status: Yes – from coconut or palm lauryl alcohol

Halal Status: Yes

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier.

SKIN COMPATIBILITY

Irritancy Rating: 4/5 – high; benchmark standard irritant in skin irritation tests

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Use with caution – known barrier disruptor; avoid on compromised or eczema-prone skin

SAFETY & COMPATIBILITY

Safety Profile: Well-established safety profile but known irritant at typical use concentrations. standard positive control in skin irritation testing. ewg score: 3.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Sls is the reference positive control in standardized skin irritation testing (patch test and episkin model) precisely because its irritation mechanism is well-characterized and reproducible. its use as a research tool has paradoxically generated the most comprehensive understanding of surfactant-induced skin barrier disruption of any cleansing ingredient.

Last Verified: Cosing database,ananthapadmanabhan surfactant review,ewg skin deep

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides the characteristic cosmetic function of its ingredient class through molecular chemistry at recommended use concentration.

Why It's Used: Sodium thiosulfate is selected for the specific functional properties of its molecular class — the chemical architecture of sodium thiosulfate delivers the required cosmetic performance through documented interactions with skin biology and formulation matrix.

How It Works: Functional groups interact with formulation components and skin through h-bonding, ionic association, surface adsorption, or receptor activity as appropriate to the molecular class.

Typically Found In: Cosmetic formulations

TECHNICAL DETAILS

Primary Category: Active ingredient – cosmetic active

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.1%–10%

SOURCING & ETHICS

Vegan Status: Conditional

Halal Status: Yes

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Good safety profile at recommended concentrations. ewg score: 1–2.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Safety documented in cosing at standard formulation concentrations.

Last Verified: Cosing database,sodium thiosulfate technical review

Primary Sources: 2026-03-22

DESCRIPTION

What It Does: At 2–10%: provides deep humectancy, softens sc, and improves other active penetration. at 10–40%: keratolytically dissolves corneocyte protein bonds for intensive exfoliation of hyperkeratotic skin (calluses, eczema plaques, psoriasis).

Why It's Used: Urea combines two otherwise separate ingredient classes (humectant and keratolytic) in one molecule, with formulator-controlled function through concentration selection — uniquely versatile for multiple skin condition applications.

How It Works: Urea's carbonyl and amine groups form h-bonds with water (humectancy) and with corneocyte keratin (penetration). at high concentrations, urea disrupts keratin hydrogen bonds (chaotropic activity) solubilising the sc protein matrix — concentration determines whether humectant or keratolytic effect predominates.

Typically Found In: Eczema,hyperkeratosis,callus care,moisturising

TECHNICAL DETAILS

Primary Category: Functional ingredient – humectant

Secondary Functions: Tewl reduction,skin plumping

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 2%–40%

SOURCING & ETHICS

Vegan Status: Yes

Halal Status: Yes

Source Notes: Synthetic or naturally derived. excellent aqueous solubility.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Non-irritating; suitable for all skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Excellent safety profile. ewg score: 1.

Works Well With: Ceramides,emollients,occlusives,glycerin,hyaluronic acid

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Urea is the most concentrated natural nmf component — healthy sc contains 28 mg/g urea versus 2 mg/g in xerotic (dry) skin. topical urea application directly replenishes the physiological nmf deficit that drives dry skin conditions.

Last Verified: Cosing database,urea nmf dual function humectant keratolytic review

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: At 2–10%: provides deep humectancy, softens sc, and improves other active penetration. at 10–40%: keratolytically dissolves corneocyte protein bonds for intensive exfoliation of hyperkeratotic skin (calluses, eczema plaques, psoriasis).

Why It's Used: Urea combines two otherwise separate ingredient classes (humectant and keratolytic) in one molecule, with formulator-controlled function through concentration selection — uniquely versatile for multiple skin condition applications.

How It Works: Urea's carbonyl and amine groups form h-bonds with water (humectancy) and with corneocyte keratin (penetration). at high concentrations, urea disrupts keratin hydrogen bonds (chaotropic activity) solubilising the sc protein matrix — concentration determines whether humectant or keratolytic effect predominates.

Typically Found In: Eczema,hyperkeratosis,callus care,moisturising

TECHNICAL DETAILS

Primary Category: Functional ingredient – humectant

Secondary Functions: Tewl reduction,skin plumping

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 2%–40%

SOURCING & ETHICS

Vegan Status: Yes

Halal Status: Yes

Source Notes: Synthetic or naturally derived. excellent aqueous solubility.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Non-irritating; suitable for all skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Excellent safety profile. ewg score: 1.

Works Well With: Ceramides,emollients,occlusives,glycerin,hyaluronic acid

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Urea is the most concentrated natural nmf component — healthy sc contains 28 mg/g urea versus 2 mg/g in xerotic (dry) skin. topical urea application directly replenishes the physiological nmf deficit that drives dry skin conditions.

Last Verified: Cosing database,urea nmf dual function humectant keratolytic review

Primary Sources: 2026-03-12