Colorant, Pigment & Dye Testing
Compare the color and performance of a documented reference and candidate formulation. Pigments, soluble dyes and masterbatches pose different identity, dispersion and exposure questions; a visual match does not establish chemical equivalence or biological safety.
| Class / examples | What to document | Possible comparison |
|---|---|---|
| Inorganic pigments: titanium dioxide (TiO2), iron oxides, carbon black | Surface treatment, particle grade, impurities and loading | Opacity/tint, dispersion and appropriate identity/elemental evidence; examples do not imply device-use approval. |
| Organic pigments: phthalocyanine, quinacridone, azo families | Exact pigment identity, supplier grade and lot; family names cover different substances | Color strength, dispersion, light/thermal stability and targeted impurity/extraction questions. |
| Soluble dyes | Solvent/carrier, solubility, exact identity and concentration | Bleeding, migration and stability under intended contact conditions. |
| Masterbatch / carrier / additives | Carrier resin, let-down ratio, dispersants, stabilizers and processing | Final molded-part color and dispersion; evaluate the complete formulation, not just neat pigment. |
Specify the color measurement, not just a Delta E
Agree CIELAB coordinates and the chosen color-difference equation (Delta E), reference standard, illuminant, observer, measurement geometry, specular included/excluded conditions and instrument calibration. Surface gloss, texture, thickness, backing, translucency and specimen preparation change results. ASTM D2244-25 covers instrumental color-coordinate differences; a tolerance must be agreed for your product, not inferred from the method.
Identity, dispersion and stability are selected questions
Use CAS and Colour Index (CI) identifiers where available, supplier grade, lot, purity specifications and loading. Agree microscopy/dispersion, spectroscopy or targeted chemistry where they answer a stated gap. Define processing heat, light, moisture, chemicals and aging exposures before selecting stability checks. Extraction/migration and toxicological work depend on contact, duration, dose and formulation—not a default panel.
Medical-device color additives: permission is use-specific
FDA describes medical-device color-additive provisions, listed uses and restrictions. Inventory inclusion, food use, a supplier claim or a matched color does not establish approval for every medical-device use. Check exact substance, intended device/contact, applicable listing and restrictions with qualified regulatory specialists. Chemical characterization and risk-based biological evaluation remain separate.
Give providers a comparable buyer brief
State the decision and acceptance criteria, then identify reference and candidate samples. Methods and sample allocations are proposals to agree, not an automatic panel.
- Family, supplier grade/lot, additives, colorant loading, filler and recycled/regrind content where known; mark unknowns explicitly.
- Pellet, powder, film, coupon or finished-part form; thickness, molding/extrusion/cure history and direction.
- Conditioning, service temperature, chemicals, load, aging and cleaning/sterilization history.
- Available sample quantities, destructive-test allowance, drawings/data sheets, required report, budget and provider location.
Sample considerations
- Reference and candidate finished specimens with matching thickness, surface and processing history.
- Document formulation and known changes privately; never infer unknown resin or colorant identity.
Laboratories with relevant capabilities
No directory profile currently documents this specific capability. Submit a request and we will look for laboratories that cover it.
Sources and scope references
FDA — color additives for medical devices
FDA — color additive inventories
Related testing briefs
Plastics testing and material families
Confirm standard edition, jurisdiction and actual laboratory scope. Service references are not partnerships or endorsements.