Common Name(s): Phaseolus radiatus seed starch,natural biopolymer,film-former texture absorbent

CAS Number: N/a

DESCRIPTION

What It Does: Phaseolus radiatus seed starch absorbs surface sebum and cosmetic oils through its porous granule structure, provides a silky soft-focus powdery finish on skin from the biopolymer particle's low friction coefficient, forms a breathable protective film on skin and hair, and acts as an excipient carrier or encapsulation matrix for actives in powder formulations.

Why It's Used: Formulators choose phaseolus radiatus seed starch as a biodegradable, renewable alternative to synthetic polymers (ptfe, nylon, polyethylene) in powder cosmetics — providing equivalent or superior absorbency and skin feel without microplastic regulatory concerns under eu regulation 2023/2055. natural starch granules have an intrinsically soft, semi-crystalline structure (mohs hardness ~1) that spreads smoothly on skin without abrasion, making them preferred over silica or talc when maximum gentleness is required. modified versions (cross-linked, esterified) extend the range of performance from pure powder through gel-forming to film-forming applications.

How It Works: Phaseolus radiatus seed starch works through the physical properties of its semicrystalline polysaccharide granule architecture: (1) oil absorption — starch granules are semicrystalline spheres (amylose crystalline domains surrounded by amorphous amylopectin matrix) with a porous surface and internal channels. surface sebum and oil penetrate the granule via capillary action into these channels and are immobilised by van der waals forces with the polysaccharide chains — providing oil-mattifying at the skin surface; (2) soft-focus texture — granule diameter (5–50 μm, depending on source) and smooth spherical morphology provide low-friction glide between skin surface and the applying finger/brush, with the semicrystalline granule structure being soft enough to deform without sharp edges; (3) film formation — when wetted, starch granules gelatinise (crystalline structure melts to amorphous hydrogel) above 60°c during processing, cooling to form a continuous film. modified starches with crosslinks maintain film integrity without complete gelatinisation; (4) biodegradation — amylase enzymes in soil rapidly hydrolyse the α-1,4 and α-1,6 glycosidic bonds, providing complete mineralisation to co₂ and water — zero environmental persistence compared to synthetic polymer particles.

Typically Found In: Powders,dry shampoos,biodegradable cosmetics

TECHNICAL DETAILS

Primary Category: Active ingredient – cosmetic active

Secondary Functions: Skin conditioning

Application Areas:

Typical Concentration Range: 0.5%–30%

SOURCING & ETHICS

Vegan Status: Conditional - supplier confirmation required

Halal Status: Unverified - supplier confirmation required

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier. [audit 2026-07-29 rev2: the record's own source_notes does not assert a non-animal origin, or instructs the reader to verify with the supplier; "yes" asserts knowledge the record does not hold. determination requires shariah-panel sign-off.]

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

Starch granule oil absorption capacity: oil absorption capacity (oac) of biopolymer powders correlates with granule porosity and internal surface area. rice starch (3–8 μm granules, high surface area) oac ~1.0 g oil/g; tapioca starch (15–35 μm, lower surface area) oac ~0.8 g/g; corn starch (10–25 μm) oac ~0.9 g/g. cross-linked modified starches maintain granule integrity under mechanical stress providing higher effective oac in use conditions. silica (oac ~2.5 g/g) outperforms starches on pure absorbency but the skin feel advantage of the softer biopolymer — particularly the non-abrasive, cushioned texture — justifies the lower oac for sensitive skin powders.

Last Verified: 2026-03-12

Primary Sources: Cosing database,starch biopolymer cosmetic application review