The 12 IQC Testing Standards for Raw Materials: How to Ensure Quality at the Source?

Have you ever wondered what kind of "scrutiny" every single drop of raw material undergoes before a skincare product even enters the production line?

Many people assume quality control happens right before the finished product leaves the factory. But for professional cosmetic OEM/ODM factories, the first gate of quality control is closed long before that—at the moment raw materials enter the warehouse. This gate has a professional name: IQC (Incoming Quality Control).

According to prevailing quality management theories in manufacturing, raw materials account for as much as 50% of the four major elements affecting product quality, far exceeding production processes (approx. 20%) and design (approx. 25%). In other words, half the battle of whether a final product is good or not is won or lost the moment raw materials are warehoused.

This logic is corroborated by real data in the cosmetics industry. The EU Safety Gate rapid alert system's 2024 Annual Report, released in March 2025, shows that a record 4,237 product safety warnings were logged in 2024—the highest since the system's inception in 2003. Cosmetics ranked first among all product categories with a 36% share, surpassing toys and electrical appliances. Chemical risks (such as residues of prohibited ingredients) were the primary trigger for these warnings, accounting for 49% of all alerts.

The lesson behind these numbers is clear: the root cause of problematic products is often not a mistake on the production line, but a failure in raw material control at the source.

Why is IQC So Crucial?

Under the framework of ISO 22716 (the international cosmetic GMP standard), all raw materials entering production must undergo identity verification, purity testing, and microbial quality confirmation. Any material failing to meet specifications is strictly prohibited from entering production.

In December 2025, the US FDA officially released the Draft Guidance for Industry: Mandatory Recall Authority for Cosmetics under MoCRA, explicitly stating that when evaluating whether to initiate a mandatory recall, the FDA will directly reference raw material testing data, production equipment sample analysis results, and adverse event reports. This means IQC records for raw materials have evolved from internal quality control tools into a legal chain of evidence for regulatory compliance.

Below are the 12 standard IQC testing items executed at our factory during the raw material receiving process. Through these 12 checkpoints, you can see how a batch of qualified raw materials is "certified."

The 12 IQC Testing Standards

Test Item 01: Appearance Inspection

• Purpose: Verify if the physical state of the raw material matches the purchased specifications.

• Content: Visually or via an industrial light box, check the color, transparency, and form (liquid/powder/cream/flake) against the Raw Material Spec Sheet. Anomalies include: abnormal discoloration, clumping, phase separation, and foreign matter contamination.

• Applicable Materials: Almost all raw materials, especially colorants, plant extracts, emulsifiers, and active ingredients.

• Criteria: Compare with the supplier's standard reference sample (retained sample). If the deviation exceeds the acceptable range, it is deemed unqualified, triggering a return or concession acceptance process.

Test Item 02: Odor Check

• Purpose: Identify if the raw material has oxidized, degraded, or suffered cross-contamination.

• Content: Olfactory evaluation by trained inspectors at a specified temperature (usually room temperature 25°C), compared with the retained sample's odor.

• Why it's Critical: Natural oils (e.g., squalane, jojoba oil) and protein-based raw materials are highly prone to oxidative rancidity. Odor is the fastest indicator of deterioration. Discovering an off-odor only after batch production would result in the scrapping of the entire batch, causing massive losses.

Test Item 03: pH Testing

• Purpose: Confirm the acidity/alkalinity of the raw material meets formulation requirements, preventing system instability after dosing.

• Method: Use a calibrated pH meter to measure a raw material aqueous solution prepared at a specified concentration.

• Impact: pH deviation directly affects product stability, preservative system efficacy, and even the efficacy expression of active ingredients. ISO 22716 requires verification of critical chemical parameters (including pH) for every incoming batch.

Test Item 04: Viscosity Testing

• Purpose: Verify if rheological raw materials like thickeners and emulsifiers match specifications.

• Method: Use a rotational viscometer (e.g., Brookfield) to measure dynamic viscosity at specified speeds and temperatures, typically in mPa·s.

• Typical Application: For thickeners like carbomers, xanthan gum, and hydroxyethyl cellulose, if batch-to-batch viscosity fluctuates beyond ±10%, it will directly cause the finished product to feel too thin or too hard, affecting formula reproducibility.

Test Item 05: Refractive Index (RI)

• Purpose: Rapidly identify the identity and purity of liquid raw materials, assisting in adulteration detection.

• Method: Use an Abbe refractometer to measure the RI value at 25°C.

• Application: Commonly used for rapid verification of plant oils and alcoholic solvents (e.g., ethanol, propylene glycol). Every chemical substance has a fixed RI characteristic value; a significant deviation from the reference value indicates the raw material may have been diluted or substituted.

Test Item 06: Specific Gravity / Density

• Purpose: Further confirm the concentration and purity of liquid raw materials, serving as corroboration for the refractive index.

• Method: Use the pycnometer method or a digital density meter (e.g., Anton Paar), with precision up to 0.001 g/cm³.

• Typical Application: Purity checks for glycerin, silicone oils, and various concentrated plant extracts. Low density usually indicates excessive solvent content, meaning the raw material has been diluted.

Test Item 07: Moisture Content

• Purpose: Control the moisture content of powders and plant powders to prevent microbial growth caused by excessive water activity.

• Method: Karl Fischer Titration or Loss on Drying (LOD), with the former offering higher precision.

• Importance: If the moisture content of powder raw materials (e.g., collagen powder, niacinamide powder, plant extract powders) exceeds the limit, clumping and mold may occur during warehousing. Once put into production, it will also disrupt the aqueous phase balance of the emulsion system, posing a hidden risk to batch stability.

Test Item 08: Heavy Metals Testing

• Purpose: Screen for the risk of excessive harmful heavy metals such as lead (Pb), mercury (Hg), arsenic (As), and cadmium (Cd).

• Method: ICP-MS (Inductively Coupled Plasma Mass Spectrometry) or AAS (Atomic Absorption Spectroscopy), currently the highest-precision testing methods recognized internationally.

• High-Risk Materials: Colorants (especially iron oxides, mica), natural mineral muds, plant extracts. ISO/TR 17276 is the globally accepted reference document for cosmetic heavy metal screening methods.

Test Item 09: Microbial Limit Test

• Purpose: Confirm that the Total Aerobic Microbial Count (TAMC), Total Yeast and Mold Count (TYMC), and specific pathogens (Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Candida albicans) are all within acceptable limits.

• Applicable Standards: ISO 17516 and ISO 22717/22718 serve as the internationally accepted reference framework.

• Key Focus: Natural plant ingredients, aqueous ingredients (e.g., aloe juice, floral waters), and animal-derived ingredients (e.g., beeswax, silk protein) are high-risk categories for microbial contamination and should have increased sampling frequencies.

• Impact: Loss of microbial control at the raw material end can lightly affect the stability of the finished product's preservative system, or heavily lead to batch product recalls. Among the record 4,237 safety warnings logged by the EU in 2024 mentioned above, chemical and microbial risks were the two core triggers.

Test Item 10: Active Ingredient Assay

• Purpose: Verify if the actual concentration of key functional active ingredients in the raw material meets the promised specification value.

• Method: Select HPLC (High-Performance Liquid Chromatography), GC (Gas Chromatography), or UV-Vis (Ultraviolet-Visible Spectrophotometry) based on the raw material type.

• Impact: If the supplier's CoA (Certificate of Analysis) shows qualified content, but the factory's re-test finds it low, it highly likely means the raw material has been diluted or adulterated, and a Non-Conformance Report (NCR) procedure should be initiated immediately.

Test Item 11: Restricted/Prohibited Substance Screening

• Purpose: Proactively screen for ingredients prohibited or restricted by target market regulations.

• Core Regulatory Frameworks (Current as of 2026):

  • EU: EC No 1223/2009, Annexes II to VI (Prohibited/Restricted/Colorants/Preservatives/UV Filters lists).

  • US: MoCRA 2022 + FDA Prohibited/Restricted ingredient lists; the FDA's Dec 2025 report noted 51 PFAS substances detected in 1,744 cosmetic formulations, urging industry focus.

  • China: NMPA's Prohibited and Restricted Cosmetic Ingredient Catalog (continuously updated in 2025).

• Substances of Very High Concern (SVHC): Formaldehyde releasers, phenolic preservatives, parabens (restricted in some categories), 1,4-dioxane (a byproduct of ethoxylation).

Test Item 12: Packaging Material Compatibility

• Purpose: Confirm that the raw material (or the formulation based on it) does not undergo chemical migration, corrosion, or adsorption with the final packaging materials used.

• Content:

  • Extract/Soaking Liquid Analysis: Soak packaging in the formulation (or a representative liquid) and test for migration of plasticizers, heavy metals, or off-odor substances into the raw material.

  • Long-term Compatibility Observation: Store at high (40°C), room, and low (4°C) temperatures to observe if discoloration, swelling, or leakage occurs at the interface between the packaging and the contents.

• Why it's in IQC: For inner packaging materials in direct contact with raw materials (e.g., silicone valve membranes, PP caps, aluminum foil bags), compatibility failure will directly contaminate the raw material. Therefore, compliant factories include inner packaging in the IQC management system at the same level.

How to Build an Operable Raw Material IQC System?

The 12 testing items only cover "what to do." To make IQC operate effectively, the following systematic support is required:

① Raw Material Specification Sheet

Every raw material must have a complete specification sheet covering: identity information (INCI name, CAS number, supplier), physicochemical parameter ranges, microbial limits, restricted substance declarations, storage conditions, and shelf life. ISO 22716 explicitly requires that the specification sheet is the foundational document for raw material traceability.

② Risk-Based Sampling Plan

Not every batch requires 100% full inspection for every item. The logic is typically tiered:

• Class A (Actives, High-Risk): Full-item testing for every batch.

• Class B (Auxiliaries, Standard Basics): AQL sampling; partial items released based on CoA.

• Class C (Packaging Materials): Full inspection for the first batch; periodic re-testing thereafter.

③ Non-Conforming Material Handling Process (NCR + CAPA)

Any raw material failing IQC must be immediately isolated and tagged, triggering a Non-Conformance Report (NCR). The quality team evaluates it to decide on return, concession acceptance (with conditions), or destruction. Simultaneously, a Corrective and Preventive Action (CAPA) is triggered to analyze the root cause and feed it back into the supplier management system.

Are you looking for a reliable Skincare factory?

Are you seeking a trusted partner to launch or scale your skin care line? At Deva Skincare,we specialize in developing safe formulations that combine barrier science with clean, compliant manufacturing.

Our R&D team and certified production facilities deliver turnkey OEM/ODM solutions tailored to your target market’s regulatory and consumer expectations.

By collaborating with Deva Skincare, you gain access to industry-leading expertise and innovative formulations that set your brand apart in the competitive global market. Contact us today to discover how we can help you succeed.

Conclusion: IQC is a Cost, but More Importantly, a Moat

Under cost pressures, many factories tend to reduce the scope and frequency of raw material testing. This logic seems to save a few hundred dollars in testing fees in the short term, but once raw material issues lead to a batch recall or an import ban by European or American market regulators, the losses can easily reach hundreds of thousands or even millions of dollars—not to mention the long-term damage to brand reputation.

source quality control has become a market access threshold for brands going global, not just a nice-to-have bonus.

For independent site sellers and emerging beauty brand owners who are serious about building their brands, choosing an OEM/ODM factory with a complete raw material IQC system means your product stands on the right side of compliance and safety from the very first batch.

If you wish to learn more about our raw material testing system and laboratory capabilities, feel free to send us an inquiry. We will provide detailed factory quality manuals and sample testing reports. Deva Skincare