TBC - The Bath and Care Halo Guard Sunstick SPF50 PA ++++

DESCRIPTION

What It Does: Provides uvb filtration and co-solvent function enabling higher uv filter concentrations in high-spf formulas.

Why It's Used: Spf enabler — homosalate's co-solvent function dissolves other uv filters more completely, enabling higher concentrations and therefore higher achievable spf in fluid-texture formulations.

How It Works: Cyclohexyl salicylate absorbs uvb (λmax 306nm, εmax 4,290 — moderate). also acts as oily co-solvent dissolving avobenzone, octinoxate, and other uv filters. photostable cyclohexyl structure.

Typically Found In: High-spf combination sunscreens

TECHNICAL DETAILS

Primary Category: Active ingredient – cyclohexyl salicylate uvb filter

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: Up to 15% (eu), 10% (us fda)

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 max 15% (sccs 2019 reduced limit). fda: 10%. potential endocrine activity at high concentrations. ewg score: 4.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Homosalate's maximum concentration in eu was reduced from 10% to 15% in sccs opinion 2019 (counter-intuitively raised, not reduced) specifically to enable effective uv filter dissolution — demonstrating that homosalate's primary value is as a co-solvent enabling other uv filters to function, not solely as a uv filter itself.

Last Verified: Cosing database,fda uv filter otc monograph,sccs homosalate opinion

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides uvb-uva-ii uv protection and essential avobenzone photostabilisation.

Why It's Used: The essential combination partner — octocrylene's dual uv filter + avobenzone photostabilisation function makes it virtually irreplaceable for durable broad-spectrum chemical sunscreens requiring uva-i coverage.

How It Works: Cyanocinnamate chromophore absorbs uvb-uva-ii (λmax 303nm). triplet energy transfer from excited avobenzone to octocrylene photostabilises avobenzone (>90% efficiency at 3:1 avobenzone:octocrylene ratio). hydrophobic character enhances water resistance.

Typically Found In: Broad-spectrum sunscreens,avobenzone-containing formulas

TECHNICAL DETAILS

Primary Category: Active ingredient – uv filter and photostabiliser

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: Up to 10% (eu), 10% (us fda)

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 max 10%. fda: 10%. ewg score: 3. recent benzophenone impurity concerns from aged product hydrolysis under study.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Octocrylene's triplet energy transfer photostabilisation of avobenzone operates via a dexter electron exchange mechanism: excited-state avobenzone (triplet) transfers excitation energy to octocrylene via orbital overlap, allowing avobenzone to return to its ground state uv-absorbing form without photodegradation. this energy transfer is only efficient at close molecular proximity — requiring intimate mixing of the two compounds in the formulation oil phase.

Last Verified: Cosing database,fda uv filter otc monograph,sccs octocrylene opinion

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Forms an occlusive lipid film reducing tewl, softens and smooths skin, and provides a long-lasting emollient effect from the hydrocarbon film's low volatility and high stability.

Why It's Used: The most extensively safety-tested cosmetic emollient — cosmetic-grade mineral oil has a 80+ year safety record with zero documented systemic absorption or sensitisation concerns. its inertness makes it the reference standard for hypoallergenic baby care.

How It Works: Linear and branched c15–c40 paraffin hydrocarbons form a non-polar surface film with water contact angle ~0° (spreads on skin). the film reduces tewl by 40–60% through physical occlusion of the sc surface; the inert hydrocarbon chains have no biological interaction with skin proteins explaining the exceptional safety and non-sensitising profile.

Typically Found In: Baby care,emollient bases,sensitive skin

TECHNICAL DETAILS

Primary Category: Functional ingredient – emollient

Secondary Functions: Barrier sealing,softening

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 1%–80%

SOURCING & ETHICS

Vegan Status: Yes

Halal Status: Yes

Source Notes: Plant-derived, synthetic or animal-derived. verify source.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 1/5 – low; formulation-dependent

Sensitivity Concerns: Non-irritating.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

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

Works Well With: Humectants,ceramides,actives as carrier

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Cosmetic-grade mineral oil (pharmaceutical grade, fully refined) is distinct from industrial mineral oils — iarc carcinogen designation applies to untreated/mildly treated industrial mineral oils, not the highly refined pharmaceutical/cosmetic grade used in personal care.

Last Verified: Cosing database,mineral oil cosmetic grade safety review

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Tocopherol neutralizes free radicals that damage skin cells, protects cell membranes from lipid peroxidation, moisturizes, and helps maintain a healthy skin barrier.

Why It's Used: It is used as both a skin-active antioxidant and a formulation stabilizer (preventing oxidation of other ingredients). it has decades of safety and efficacy evidence and works synergistically with vitamin c.

How It Works: As a chain-breaking antioxidant, tocopherol donates hydrogen atoms to interrupt lipid peroxidation chain reactions. it is regenerated by vitamin c (ascorbic acid) in the vitamins c+e antioxidant cycle, creating a more durable antioxidant defense.

Typically Found In: Moisturizers,serums,oils,sunscreens,eye creams,lip balms,antioxidant formulations,haircare products

TECHNICAL DETAILS

Primary Category: Active ingredient – antioxidant/vitamin e

Secondary Functions: Emollient,formulation stabilizer,barrier support

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.1%–1% (typical: 0.1–0.5% as active; higher as formulation antioxidant)

SOURCING & ETHICS

Vegan Status: Yes – plant-derived (soybean, sunflower, wheat germ oil) or synthetic

Halal Status: Yes – plant-derived or synthetic

Source Notes: Natural d-alpha-tocopherol is derived from plant oils and is more bioactive. synthetic dl-alpha-tocopherol is less expensive. tocopherol acetate (tocopheryl acetate) is the more stable ester form.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low; rare contact sensitivity reported

Comedogenicity Rating: 2/5 – mildly comedogenic at higher concentrations; formulation-dependent

Sensitivity Concerns: A small percentage of people report contact sensitization to tocopherol, particularly with leave-on products. comedogenicity risk is higher in oil-heavy formulations.

Safe for Sensitive Skin: Generally yes; perform patch test if history of vitamin e sensitivity

SAFETY & COMPATIBILITY

Safety Profile: Very safe; widely used. ewg hazard score: 2–3 (depending on concentration). no significant systemic concerns from topical use.

Works Well With: Ascorbic acid (vitamin c) – synergistic antioxidant pair,ferulic acid – stabilizes and boosts both c and e,ceramides,spf,retinol

Avoid Combining With: Very high concentrations of benzoyl peroxide may oxidize tocopherol; potential comedogenicity concerns in acne-prone skin when in heavy oil bases

SCIENTIFIC NOTE

The combination of vitamin c, vitamin e, and ferulic acid (the 'ce ferulic' formulation) provides fourfold photoprotection against uv-induced free radical damage – a synergy documented in landmark research by pinnell et al.

Last Verified: Cosing database,cir safety assessment,pinnell et al. (2005) journal of investigative dermatology,efsa panel on food additives

Primary Sources: 2026-03-12