How to Check if a Cosmetic Factory Follows GMP During Production

Certificate versus practice: what GMP really means

Good Manufacturing Practice for cosmetics is a set of principles covering premises, equipment, personnel, raw materials, production, quality control, documentation and complaint handling. Internationally, ISO 22716 is the most widely referenced cosmetic GMP guideline, and national regulators, including the Thai FDA, set their own requirements for licensed manufacturers.

A certificate confirms that an auditor assessed the system on specific dates and for a defined scope. Between audits, standards can slip: a busy season, staff turnover or a new product line can all put pressure on procedures. That is why buyers should treat the certificate as an entry ticket, not proof of everyday behaviour.

Start your **supplier verification** with the certificate itself:

• Check the legal company name and site address match the factory that will actually produce your product.
• Read the scope: does it cover the product types you need, for example emulsions, powders or aerosols?
• Note the issue and expiry dates and the issuing body, then confirm with that body if you have doubts.

Once the paperwork aligns, shift your focus to how GMP is practised during production. The rest of this guide covers what to look at and what to ask for.

Batch records: the most revealing document

If you can only check one thing, ask to see a completed batch manufacturing record from a recent production run, with confidential formula details redacted. A well-kept record shows the factory controls each step rather than relying on memory.

What a good batch record typically contains:

• **Batch number** linked to the finished product and its labelling.
• **Raw material lot numbers** for every ingredient used, with weights recorded and verified by a second person.
• **Equipment used**, including confirmation it was cleaned and released before use.
• **Process parameters**: temperatures, mixing speeds, times and pH, with actual values recorded against targets.
• **In-process checks** and their results.
• **Signatures and dates** at each critical step, by trained operators and supervisors.
• **Deviations** noted and investigated, not left blank or hidden.

Red flags include records completed in the same handwriting and pen for an entire batch, values that are identical every time, missing signatures, or records that are clearly filled in after the fact. A record with a documented deviation and a sensible investigation is often a better sign than a suspiciously perfect one, because it shows the system catches problems.

What to observe on the production floor

Whether you visit in person, send a third-party auditor or request a live video walkthrough, focus on observable behaviour during an actual production run:

• **Gowning and hygiene**: staff wearing appropriate clothing, hair covers and gloves; handwashing stations used; changing areas separated from production.
• **Material flow**: raw materials, work in progress and finished goods kept in clearly separated areas, with status labels such as quarantine, approved or rejected.
• **Line clearance**: before a new batch starts, the line is checked and documented as free of previous product, labels and packaging.
• **Equipment status labels**: tanks and fillers marked as clean, in use or awaiting cleaning.
• **Environmental controls**: appropriate air handling for the product type, pest control measures, and no obvious sources of contamination.
• **Weighing area**: calibrated scales with visible calibration status, and dispensing done under control.

Ask operators simple questions such as what they do if a parameter is out of range. Confident, consistent answers suggest training is real. A **skincare manufacturer in Thailand** that runs GMP properly will usually be comfortable letting you see these details, while still protecting other clients' confidential formulas.

Quality control and release testing

GMP depends on a functioning quality control system that is independent from production. Ask how the factory decides that a batch is fit to release:

• **Incoming raw materials**: are they sampled and tested or checked against supplier certificates before use? Is there an approved supplier list?
• **Packaging components**: are bottles, jars and pumps inspected for defects and cleanliness?
• **Finished product testing**: typical checks include appearance, colour, odour, pH, viscosity and microbiological testing where relevant. Ask which tests are done on every batch.
• **Retained samples**: does the factory keep samples of each batch for a defined period to investigate future complaints?
• **Release authority**: who signs the release, and are they part of a quality function separate from production?
• **Out-of-specification handling**: what happens when a result fails? Ask for an example of a past investigation.

Request a sample certificate of analysis from a previous batch so you can see the format and parameters. For your own products, agree in writing which tests will be performed and what documentation you receive with each shipment. This is also the right moment in **product development** to set specifications with acceptable ranges, so release decisions are objective.

Ongoing monitoring after the first order

GMP compliance is not a one-time check. Build monitoring into your relationship:

• **Pre-shipment inspection**: have a third party inspect finished goods before they leave the factory, checking quantity, packaging, labelling and sampling for basic tests.
• **Independent lab testing**: periodically send retained or market samples to an external lab to confirm key parameters.
• **Periodic audits**: schedule audits at sensible intervals, and after significant changes such as a new production line or ownership change.
• **Complaint tracking**: share customer complaints with the factory and review their investigations and corrective actions.
• **Change control**: require the factory to notify you before changing raw material suppliers, processes or packaging components.

Some brand owners work through a managed model, where one partner coordinates multiple production sites. For example, 5FINE works through a **partner factory network** of GMP-certified facilities and coordinates quality checks across them. Others source directly, sometimes finding candidates on verified marketplaces such as THAIMOST. In either model, the brand owner should still understand the controls in place and keep records of their own checks, because responsibility to customers and regulators ultimately sits with the brand on the label.

Red flags that should pause your order

Keep this list handy during evaluation and production:

• **Refusal to show any batch records**, even redacted, or to allow any form of audit.
• **Certificate details that do not match** the company or site producing your goods, or suggest subcontracting you were not told about.
• **No separation** between raw materials, quarantined goods and finished products.
• **Handwritten records completed in bulk**, or entries that look copied from batch to batch.
• **No retained samples** and no clear way to trace a finished product back to its raw material lots.
• **Defensive answers** to basic questions about deviations, cleaning or release decisions.
• **Promises that every product is fully certified** without specifics for your product.

One red flag does not automatically disqualify a factory, but it should trigger a clear request for evidence and a written corrective plan. If several appear together, it is usually wiser to pause and evaluate alternatives. Verifying GMP in practice takes some effort up front, but it protects your brand from recalls, regulatory trouble and customer complaints that are far more costly to fix later.