FDA Thailand GMP 420 explained: key requirements, the inspection forms and how audits are scored
What is GMP 420?
GMP 420 is industry shorthand for Thailand's Ministry of Public Health Notification No. 420 B.E. 2563 (2020) on production methods, production equipment and food storage: the Good Manufacturing Practice rule for food made for sale in Thailand. It was signed on 3 December 2020, published in the Royal Gazette on 9 February 2021, and took effect 60 days after the day following publication.
Before No. 420, food GMP was spread across several notifications. No. 420 repealed nine earlier GMP notifications, including Nos. 193 (2000), 298 (2006), 342 (2012) and 349 (2013), and consolidated them. The Thai FDA's explanatory notification says new producers and importers had to comply from 11 April 2021, while existing licensees had a 180-day grace period and had to comply from 7 October 2021.
For a general introduction to GMP and how cosmetics differ, read What is GMP. This article goes deeper into No. 420 itself, its categories and the forms officers actually use.
Who must comply
Clause 2 applies the notification to everyone producing food for sale, with listed exceptions.
- Restaurants and places cooking for immediate consumption are exempt unless they produce specifically controlled food, food with prescribed quality or standards, or food requiring a label, using machinery of 5 horsepower or more in total or 7 or more workers.
- Food stalls in public places.
- Salt production premises.
- Fresh fruit and vegetable packing houses covered by their own notification.
Small producers often assume a small kitchen is outside GMP entirely. If you make labelled products sold through other shops and reach the machinery or headcount thresholds, No. 420 applies. Importers are affected too: clause 6 requires importers of food for sale to hold evidence that the foreign producer meets a standard equivalent to or not lower than No. 420.
GMP 420 requirements: five basic categories plus specific requirements
The annex has two parts: basic requirements for all food plants, and additional specific requirements for three food groups.
| Basic category | Examples of annex items |
|---|---|
| 1. Location and buildings | Away from contamination sources · no accumulation around buildings · drainage · sound construction, pest-proofing · separated areas · a filling room or controlled filling area · ventilation · lighting |
| 2. Equipment and machinery | Food-contact materials · installed for cleaning · work surfaces · piping systems · cleaning · maintenance · accurate weighing and measuring |
| 3. Production control | Raw materials and additives · packaging · mixing · microbial reduction steps · filling and sealing · handling · traceability · final product · production and distribution records · non-conforming product · record keeping · internal audit |
| 4. Sanitation | Water · toilets and hand-washing · changing facilities · hand-washing in production · pest control · waste · chemicals |
| 5. Personal hygiene | Workers free of listed diseases · personal cleanliness · hand-washing and gloves · hair covers, clothing, footwear · no eating or smoking at work · training · rules for non-production visitors |
The three groups with specific requirements are: bottled drinking water, natural mineral water and filtered ice; pasteurised ready-to-drink liquid milk products; and low-acid and acidified foods in hermetically sealed containers. Producers in these groups must have a production supervisor trained on a course approved by the Thai FDA (clause 4).
The numbers you must hit
Most of No. 420 is principle-based, but some items are numeric and easy for an auditor to check.
- Test the final product, including water and ice used as ingredients, at a government or accredited laboratory at least once a year.
- Keep records and reports at least one year beyond the expiry date on the label.
- Carry out an internal quality audit at least once a year.
- For low-acid and acidified sealed foods, use a qualified thermal process authority and set an F0 value of not less than 3 minutes.
These are quick wins for an auditor. Missing last year's lab results or discarding records too early becomes a finding immediately, however clean the floor looks.
GMP 420 audit checklist: forms TS.1 to TS.5
The Thai FDA notification on auditing food premises against No. 420 (Royal Gazette, 2 April 2021) sets five audit record forms (written in Thai as
| Form | Used for |
|---|---|
| TS.1 (63) | Audit summary report |
| TS.2 (63) | Basic requirements, all plants |
| TS.3 (63) | Specific requirements: drinking water, natural mineral water or ice |
| TS.4 (63) | Specific requirements: pasteurised ready-to-drink liquid milk |
| TS.5 (63) | Specific requirements: low-acid and acidified sealed foods |
A typical plant is audited on TS.2 and summarised on TS.1; plants in the three specific groups are also audited on their group's form. The best preparation is to use the form's items as your own pre-audit checklist.
How audits are scored and what passes
The audit notification explains scoring for the basic requirements:
- Each item is rated good = 2, fair = 1, needs improvement = 0, using a decision tree.
- Items not applicable to the site are removed from the maximum score, 2 points each.
- Scores are calculated as a percentage per category.
- Specific requirements are judged pass or fail.
To pass, every basic category must score at least 60% with no major defect, and plants in a specific group must pass every specific item. A high overall score does not help: one category below 60% or a single major defect means a fail.
If nothing is being produced at the time of the audit, for example a new plant applying for the first time, officers assess readiness and evidence, then follow up once production starts.
Major defects that fail you outright
The audit notification gives examples of major defects. Close them all before audit day.
- No filling room, or contamination after the kill step cannot be controlled.
- Wrong food additive or wrong amount.
- Water or ice not up to standard, or no lab result at least once a year.
- Microbial reduction steps not controlled.
- No final-product lab result at least once a year.
- For dietary supplements, no production, distribution or recall records.
The last item matters for supplement contract manufacturers because it is about the documentation system, not machinery. A plant with excellent equipment but no records or recall procedure can still fail. See hiring a supplement OEM factory.
The Thai FDA's explanatory notification
The Thai FDA also issued an explanatory notification on No. 420 (dated 4 March 2021). Points useful for planning:
- No. 420 consolidates food GMP, but Notification No. 386 (2017) on certain fresh fruits and vegetables still applies.
- Producers in the specific groups need a production supervisor who passed a Thai FDA course or one run by an FDA-listed training body.
- Importers must source from plants with a manufacturing-system certificate equivalent to or not lower than No. 420.
- Non-compliance is punishable under section 49 of the Food Act B.E. 2522 (1979).
For importers, the Thai FDA notification of 27 November 2024 on manufacturing-system certificates for imported food sets who may issue them, requires the scope to cover the imported food, and regards a certificate with no end date as valid for at most one year from issue.
Thai GMP certificates from certification bodies, and licence renewal
Besides audits by officers, producers can obtain a manufacturing-system certificate from a certification body listed with the Thai FDA, under the 2021 Thai FDA notification on issuing such certificates.
- The certificate is valid for three years from signature, with a surveillance audit once a year.
- If the overall score across all categories is at least 85%, it is marked Excellence Level.
- The certification mark belongs on the certificate only and must not appear on product labels; any label statement about certification must follow the specific Thai FDA notification on that topic.
When renewing a food production licence, the 13 September 2022 Thai FDA notification on renewal evidence accepts either a valid manufacturing-system certificate whose scope covers the products, or a passing audit result no more than one year old.
Preparing your plant for a GMP 420 audit
- Go through TS.2 item by item, score yourself the way the officer will, and spot categories at risk of falling below 60%.
- Close every major defect first, because one is enough to fail.
- Have last year's accredited lab results for the final product, water and ice ready.
- Organise production, distribution, traceability and recall records.
- Run at least one internal audit and record findings and corrective actions.
- If you make a specific-group product, check the production supervisor's qualifications and training certificate.
Our team can review your site before the real audit; start from our contact page, or see the factory setup and GMP service.
Frequently asked questions
Does GMP 420 apply to a small bakery?
Shops cooking for immediate consumption are exempt, but producing labelled, quality-prescribed or specifically controlled food with 5 hp of machinery or 7 workers brings you under No. 420.
What score passes a GMP 420 audit?
Every basic category at least 60% with no major defect; plants with specific requirements must pass every specific item.
How many audit forms are there?
Five: TS.1 summary, TS.2 basic requirements, and TS.3–TS.5 for drinking water, pasteurised milk, and low-acid or acidified sealed foods.
Can I put a GMP mark on my label?
No. The certification body's mark must not appear on product labels; label statements about certification follow a separate Thai FDA notification.
How old can an audit result be for licence renewal?
A passing audit result must be no more than one year old, or you can use a valid manufacturing-system certificate instead.
Sources
- MOPH Notification No. 420 B.E. 2563 (2020) on production methods, equipment and food storage · Open source · Search our archive
- Thai FDA explanatory notification on No. 420 · Open source · Search our archive
- Thai FDA notification on auditing food premises against No. 420 · Open source · Search our archive
- Thai FDA notification on issuing manufacturing-system certificates, 2021 · Open source · Search our archive
- Thai FDA notification on evidence for renewing food production licences (2022) · Open source · Search our archive
- Thai FDA notification on manufacturing-system certificates for imported food (2024) · Open source · Search our archive
This article is for general information. It is not a Thai FDA ruling or legal advice, and rules change — check the latest notification or ask an expert before filing or producing.