IVD Classification in Thailand: Risk Tiers, Grouping and Special Rules

1. Key takeaways

In vitro diagnostics in Thailand are medical devices governed by the same law, but their classification follows a separate risk ladder. Beyond the risk to the individual patient, Thailand additionally weighs the public health consequences of a wrong result, and this is the single biggest difference between IVD classification logic and ordinary device classification logic. The consequence is that IVD classes cannot be guessed from reagent intuition: a seemingly simple assay may sit high on the ladder because of what a false result would do at population level. Reading the published examples together also shows the pattern behind the ladder: risk rises not only with the seriousness of the disease but with the setting in which the result is used, which is why some self-testing products and near-patient monitoring assays occupy the middle classes while screening assays for transmissible pathogens occupy the top class.

• Class 1 (low risk): clinical chemistry analysers and similar items.
• Class 2 (low to medium risk): pregnancy testing, fertility testing and some self-testing IVDs.
• Class 3 (medium to high risk): blood glucose monitoring, blood gas analysis and similar products.
• Class 4 (high risk): critical IVDs such as HIV, HBV and HCV assay reagents.
• Self-testing versus professional use, together with the consequences of a wrong result, jointly determine the IVD class; reagents must not be treated as a uniformly low-risk category.
• Two IVD-specific grouping routes exist: the IVD test kit, which groups reagents used together for one diagnostic purpose under a single kit name with analysers excluded, and the IVD cluster, available only to Class 1 and Class 2 IVDs from the same manufacturer using the same detection method within the same cluster category.
• HIV test kits are both Class 4 high-risk IVDs and on the sales licence list, and WHO Prequalification counts in the Thai reliance pathway for IVDs only, subject to a 1-year holding condition.

2. Legal basis

The IVD classification rules sit in the MoPH risk classification notification B.E. 2562 (2019), and the Thai FDA publishes classification examples that fix the typical distribution: clinical chemistry analysers at Class 1, pregnancy and fertility testing and some self-testing IVDs at Class 2, blood glucose monitoring and blood gas analysis at Class 3, and HIV, HBV and HCV assay reagents at Class 4. The grouping rules are set out in the Thai FDA grouping guideline, which defines the IVD test kit as reagents or articles used together for a specific diagnostic purpose and grouped under one kit name; analysers must be excluded from the kit and are usually handled separately as part of an IVD system, and within the approved scope replacement reagents may be supplied separately. The IVD cluster requires the same manufacturer, both devices at Thai Class 1 or Class 2, the same detection method and membership of the same cluster category as listed in Annex 7 of the guideline; Class 3 and Class 4 IVDs cannot use this grouping route. On reliance, the Thai FDA reliance notification of 4 June 2024 (B.E. 2567) accepts WHO Prequalification for IVDs only, with the same 1-year holding condition applied elsewhere in the pathway. For IVD manufacturers holding WHO Prequalification, this makes reliance the first route to evaluate, since it can substantially shorten review while sparing the product from expert panel scrutiny.

3. Expert insights

The easiest trap for an IVD company in Thailand is mapping the European IVDR classes directly onto Thai classes. The IVDR letters A, B, C and D and the Thai numbers 1, 2, 3 and 4 differ in name and in decision logic, and the mapping is not monotonic: an IVDR Class C product is not necessarily Thai Class 3. The only safe procedure is to re-judge every product against the Thai IVD ladder from first principles, weighing self-testing status and the public health consequences of a wrong result, and to state the Thai classification basis explicitly in the submission documents, so that the reviewer sees a Thai-legal argument rather than a borrowed one. Boundary questions also recur: products for testing human samples in vitro to provide diagnostic information are IVDs, while products for environmental, food or veterinary testing generally fall outside the IVD scope under the device regime, and dual-purpose products are judged by their principal mechanism of action. Keeping these boundary rules in view avoids wasted filings for products that were never devices in the first place.

4. Practical recommendations

• Classify every IVD under the Thai ladder directly, and document the reasoning in the dossier rather than citing an IVDR class as authority.
• Use the test kit grouping route for reagent panels that serve one diagnostic purpose, keeping analysers out of the kit and filed separately as part of the IVD system.
• Use the cluster route only when all conditions hold: one manufacturer, Thai Class 1 or Class 2, the same detection method and the same cluster category per Annex 7.
• Flag HIV test kits early in project planning, since they combine Class 4 status, the sales licence requirement and an analytical report at renewal.
• Where a WHO Prequalification certificate exists and is older than 1 year, evaluate the IVD reliance pathway under the 4 June 2024 (B.E. 2567) notification as a potential accelerant.

5. Verification checklist

• □ MoPH risk classification notification B.E. 2562 (2019), IVD classification rules confirmed (pending verification).
• □ Thai FDA website IVD classification examples covering pregnancy and fertility testing, blood glucose monitoring, blood gas analysis and HIV, HBV, HCV assays (pending verification).
• □ Thai FDA grouping guideline covering the IVD test kit and IVD cluster, with cluster categories in Annex 7 (pending verification).
• □ Thai FDA sales licence applicable product list including HIV test kits (pending verification).
• □ Thai FDA reliance notification of 4 June 2024 (B.E. 2567), WHO Prequalification limited to IVDs (pending verification).

How GRZAN can help. GRZAN provides medical device and IVD registration, quality system, authorised representative and local testing support across Southeast Asia, including Thailand. Our team prepares dossiers to ASEAN CSDT structure, manages submissions and deficiency responses with the Thai FDA, and supports post-market vigilance obligations. Business enquiries: info@grzanglobal.com