Every term. Defined precisely.

Amodimethicone is the INCI name for amino-functional silicones — dimethylsiloxane polymers modified with aminopropyl groups. CAS number 71750-80-6. The amino functionality provides…

Caprylyl Methicone is the INCI name for short-chain alkyl-modified silicone — dimethylsiloxane with caprylyl (C8) groups substituted onto the backbone. CAS number 17955-88-3. Non-c…

CAS 107-46-0 is the registry number for Hexamethyldisiloxane, the shortest linear silicone fluid (0.65 cSt). Linear structure means it is not subject to the cyclic silicone restric…

CAS 541-02-6 is the Chemical Abstracts Service registry number for Cyclopentasiloxane (D5), a cyclic silicone fluid. SVHC-listed under EU REACH — restricted in wash-off cosmetics a…

CAS 556-67-2 is the registry number for Cyclotetrasiloxane (D4), a cyclic silicone. SVHC-listed under EU REACH at stricter thresholds than D5. Largely eliminated from modern cosmet…

CAS 9006-65-9 is the Chemical Abstracts Service registry number for Dimethicone (Polydimethylsiloxane, PDMS) — the linear silicone polymer used as the foundation of cosmetic silico…

CAS (Chemical Abstracts Service) Number is a unique numerical identifier assigned to every chemical substance. Format: XXXXXXX-XX-X. Used in regulatory filings, safety data sheets…

Certificate of Analysis (CoA) is a quality document issued by the manufacturer for a specific batch of product, confirming the batch meets specifications. CoA typically lists measu…

Cosmetic silicone is a silicone fluid, blend, elastomer, resin, or surfactant manufactured to cosmetic-grade specifications for use in personal care formulations including skincare…

EC 1223/2009 is the European Union Cosmetics Regulation governing safety, labelling, and notification of cosmetic products sold in the EU and UK. Defines requirements for ingredien…

A crosspolymer is a polymer formed by chemically linking individual polymer chains into a network. Dimethicone Crosspolymer is the cross-linked version of dimethicone, typically su…

Cyclic siloxanes are silicone fluids with ring structures rather than linear chains. The main cyclic siloxanes are D4 (Cyclotetrasiloxane), D5 (Cyclopentasiloxane), and D6 (Cyclohe…

Cyclomethicone is a generic INCI name historically used for blends of cyclic siloxanes (typically D4, D5, and D6 mixtures). CAS number 69430-24-6. Modern INCI specifications increa…

Cyclopentasiloxane (D5) is the INCI name for a cyclic silicone with five siloxane units in a ring structure. CAS number 541-02-6. Used as a volatile carrier in skincare, haircare,…

Cyclotetrasiloxane (D4) is a cyclic silicone with four siloxane units. CAS number 556-67-2. Historically used as a volatile carrier in personal care products. Regulatory note: D4 i…

D4 is the shorthand name for Cyclotetrasiloxane (also called Octamethylcyclotetrasiloxane) — a cyclic silicone with four siloxane units, CAS 556-67-2. SVHC-listed under EU REACH at…

D5 is the shorthand name for Cyclopentasiloxane — a cyclic silicone with five siloxane units, CAS 541-02-6. Widely used as a volatile carrier fluid in personal care formulations. S…

Dimethicone is the INCI (International Nomenclature of Cosmetic Ingredients) name for polydimethylsiloxane (PDMS), a linear silicone polymer. CAS number 9006-65-9. In cosmetics, di…

Dimethicone Crosspolymer is the INCI name for cross-linked silicone elastomers — dimethylsiloxane chains chemically linked into three-dimensional networks. Typically supplied as ge…

Dimethiconol is the INCI name for dimethylsiloxane polymers terminated with hydroxyl groups (–OH) rather than trimethylsilyl groups. CAS number 70131-67-8. Higher viscosity and sub…

Diphenylsiloxy Phenyl Trimethicone is a speciality INCI name for a methyl phenyl silicone with an asymmetric three-phenyl structure. Delivers exceptionally high refractive index (1…

FDA 21 CFR 177.2600 is the United States Food and Drug Administration regulation governing rubber articles intended for repeated use in contact with food. Relevant for silicone man…

A film former is a cosmetic ingredient that creates a continuous protective layer on skin or hair after application. Silicone film formers (resins, high-viscosity dimethicones, dim…

A formulator is a cosmetic chemist who develops cosmetic and personal care product formulations — combining active ingredients, functional ingredients (like silicones), preservativ…

GHS (Globally Harmonized System of Classification and Labelling of Chemicals) is the international standard for chemical safety data sheets (SDS). GHS-format SDS consists of 16 man…

HLB (Hydrophilic-Lipophilic Balance) is a numeric scale from 0 to 20 describing whether a surfactant favors the oil phase (low HLB) or the water phase (high HLB) of an emulsion. HL…

Hydrophilic describes substances that have an affinity for water (water-loving). Hydrophobic describes substances that repel water (water-fearing). Standard silicones are hydrophob…

INCI (International Nomenclature of Cosmetic Ingredients) Name is the globally standardized naming system for cosmetic ingredients, maintained by the Personal Care Products Council…

ISO 9001:2015 is the international standard for quality management systems, published by the International Organization for Standardization. Certification requires implementation o…

A leave-on cosmetic is a personal care product designed to remain on skin or hair after application — including moisturizers, serums, leave-in conditioners, sunscreens, foundations…

Linear silicones are silicone polymers with straight chain structures (as opposed to cyclic ring structures). The main linear silicone chemistry is polydimethylsiloxane (PDMS), kno…

Methicone is the INCI name for short-chain linear polymethylsiloxane terminated with trimethylsilyl groups at one end and a monomethylsilyl group at the other (asymmetric terminati…

Organosilicon compounds are chemical substances containing silicon–carbon (Si–C) bonds. All cosmetic silicones — dimethicone, phenyl trimethicone, amodimethicone, and others — are…

PDMS — Polydimethylsiloxane — is the chemical name for the linear silicone polymer known by INCI as Dimethicone. The fundamental cosmetic silicone chemistry. PDMS consists of repea…

PEG-10 Dimethicone is the INCI name for polydimethylsiloxane modified with 10 polyethylene glycol units. CAS number 68937-54-2. Functions as a non-ionic silicone surfactant and emu…

Personal Care is the consumer product category including skincare, haircare, color cosmetics, suncare, fragrance, oral care, deodorants, shaving products, and bath products. Specia…

Phenyl Trimethicone is the INCI name for phenyl-substituted silicones — siloxane polymers with phenyl groups attached. CAS number 2116-84-9. The phenyl groups deliver higher refrac…

Polymethylsilsesquioxane is the INCI name for a silicone resin formed by hydrolysis and condensation of methyltrimethoxysilane. CAS number 68554-70-1. Functions as a film former in…

Propyl Trisiloxane is the INCI name for a short-chain trisiloxane with a propyl group substitution. A speciality silicone developed as a non-cyclic alternative to Cyclopentasiloxan…

REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) is the European Union regulation governing chemical substances manufactured or imported into the EU. Al…

Refractive Index is a measure of how much a substance bends light passing through it. Higher values produce more visible shine and gloss in cosmetic formulations. Water has a refra…

A rheology modifier is an ingredient that controls how a formulation flows, suspends solids, and behaves under shear stress. Cosmetic rheology modifiers include bentonite-based gel…

RoHS (Restriction of Hazardous Substances) is an EU directive restricting the use of certain hazardous substances (lead, mercury, cadmium, hexavalent chromium, brominated flame ret…

SDS (Safety Data Sheet) — also historically called MSDS (Material Safety Data Sheet) — is the document required by law for chemical sales in most countries, providing hazard identi…

A silicone elastomer is a cross-linked silicone polymer — typically polydimethylsiloxane chains chemically connected into three-dimensional networks. In cosmetic applications, sili…

A silicone resin is a highly cross-linked silicone polymer — typically built on silsesquioxane (Si–O–Si–O–Si network) structures. In cosmetic applications, silicone resins serve as…

A silicone surfactant is a silicone polymer modified with hydrophilic groups (typically polyethylene glycol or polypropylene glycol chains) to create surface-active properties. Use…

The siloxane bond (Si–O–Si) is the fundamental chemical linkage in all silicone polymers. The alternating silicon and oxygen atoms in the backbone give silicones their characterist…

Specific Gravity is the ratio of a substance's density to water's density (water = 1.0). Cosmetic silicones typically have specific gravities between 0.76 (Hexamethyldisiloxane) an…

SPF Boost refers to a formulation ingredient's ability to enhance the Sun Protection Factor of a sunscreen formula without itself being a UV filter. Phenyl silicones, alkyl-modifie…

Stearalkonium Bentonite is the INCI name for bentonite clay treated with stearalkonium chloride (a quaternary ammonium compound). Used as a rheology modifier in cosmetic formulatio…

SVHC (Substances of Very High Concern) is a list maintained under EU REACH of chemical substances considered to pose serious risks to human health or the environment. Substances on…

TDS (Technical Data Sheet) is the document describing a product's identity, properties, applications, and use guidance. Unlike SDS (legally mandatory, hazard-focused), TDS is a com…

TSCA (Toxic Substances Control Act) is the US federal law regulating chemical substances. All chemicals manufactured or imported into the US must be listed on the TSCA Chemical Sub…

A UV Filter is a cosmetic ingredient that absorbs or reflects ultraviolet radiation, providing sun protection. UV filters are not silicones — they are organic (chemical filters lik…

Viscosity is a measure of a fluid's resistance to flow, expressed in centistokes (cSt) at 25°C in cosmetic chemistry. Lower cSt values indicate thinner, more easily flowing fluids;…

A volatile silicone is a silicone fluid that evaporates from skin or hair without leaving residue. Volatile silicones include Hexamethyldisiloxane (0.65 cSt, evaporates in under 30…

A wash-off cosmetic is a personal care product designed to be rinsed off skin or hair after application — including shampoos, conditioners, body washes, facial cleansers, and shavi…