Reviewed by: Takahiro Sugiyama (CEO, meguri Inc.)
When you buy matcha for business use, you receive a document marked “COA” along with quotations and samples. COA stands for certificate of analysis. Even with the numbers in front of you, the document is of little use unless you know which fields to read first and which country’s standards to compare it with. This article explains the items on a matcha COA one by one, and how to compare them with Singapore’s Food Regulations, Thailand’s Ministry of Public Health notifications and Japanese standards, based on each country’s laws and government documents.
What is a certificate of analysis (COA) for matcha?
A COA is a document that shows the test results for a lot of matcha next to the specification values. A lot is a batch of product made from the same raw material under the same conditions, and its number is printed on the bag or tin. The figures on a COA apply only to the matcha with that number.
What a COA contains
A typical COA has the following fields.
| Field | Contents |
|---|---|
| Product name and grade | Product name, origin, harvest (first flush or later) and so on |
| Lot number | Which batch was tested |
| Dates | Production date, test date, issue date |
| Test items | Moisture, microbes, pesticide residues, heavy metals and so on |
| Specification and result | Upper and lower limits, the measured value, and the unit |
| Method | How it was measured |
| Laboratory | In-house or external, with the laboratory’s name and address |
| Signature | The person responsible for issuing it |
How it differs from a specification sheet
A specification sheet (spec sheet) states the quality range the product is made to. A COA is the result of actually measuring that lot. You can only tell whether the lot meets the specification by placing the COA results next to the specification values. If the spec sheet has a moisture limit but the COA has no moisture field, that item has not been checked.
How it differs from a laboratory’s test report
When a test is done by an external laboratory, the laboratory issues a test report in its own name. A supplier’s COA sometimes combines in-house results with figures from external reports, so for items usually sent to external laboratories, such as pesticide residues and heavy metals, ask for a copy of the original report as well, so that you can check the laboratory and method.
Fields to check first: lot number, dates, sample and laboratory
Before reading the numbers, check that the lot number and dates match the matcha you have. If the number is different, the results do not belong to that matcha, however good they look.
Lot number
Match the lot number on the bag or tin you received with the lot number on the COA. If the lot changes between the sample and your actual order, ask for a new COA for the lot of your order. For a product that combines several lots, also ask which lot was tested.
Production date, test date and issue date
If the test date is before the production date, the result may be for the tencha (the tea leaves used as the raw material for matcha). Whether the result is from before or after grinding into powder can change values such as moisture and microbes. How to think about shelf life is covered in Matcha Shelf Life.
Sample and laboratory
The results on a COA come from measuring a portion (sample) taken from the lot. If the document says where and how many grams were taken, read it. If not, ask how the sample was taken. If a document has no laboratory name, or if every result is “0” with no unit or method, do not use it as it is. Ask for the original test report.
How to read moisture and particle size
Moisture affects deterioration during storage, and can be compared with the figure in Thailand’s tea standard. Particle size has no legal limit. Compare it with the specification and look at how it varies from lot to lot.
Moisture
Moisture is the proportion of water in the powder, written as a percentage. In the Standard Tables of Food Composition in Japan (Eighth Revised Edition, Supplement 2023) of Japan’s Ministry of Education, Culture, Sports, Science and Technology, the moisture of matcha is 5.0g per 100g. Thailand’s Ministry of Public Health Notification No. 196 “Tea” sets the moisture of tea at 8% or less. For flavoured dried tea packed in sealed containers (prepared tea), it is 6% or less.
Matcha absorbs moisture easily, so the moisture on a COA is the value at the time of production. It can rise during storage after arriving in a hot country, so take care with storage after delivery.
Particle size
Particle size is the fineness of the powder. On a COA it is written as a median in µm (micrometres, one thousandth of a millimetre), or as the proportion that passes through a sieve of a given mesh. The meaning of the number changes depending on which is used, so compare it with the specification written the same way. How particle size relates to mouthfeel is covered in How to Judge Matcha Quality.
Microbiological items, and the Singapore and Thai standards
Singapore and Thailand have legal microbiological standards that apply to tea and powdered beverages. However, neither country sets a legal limit for matcha itself for total plate count or for yeast and mould, which often appear on a COA. These values are usually the supplier’s in-house specifications.
What the items mean
| Item | Meaning |
|---|---|
| Total plate count (TPC) | Number of microbes that grow when cultured under set conditions. An indicator of hygiene |
| Coliforms | A group of bacteria with properties similar to E. coli. An indicator of hygiene control |
| E. coli | A bacterium that indicates faecal contamination |
| Yeast and mould | An indicator of moisture and storage conditions |
| Salmonella and others | Bacteria that cause food poisoning (pathogens) |
The unit CFU/g is the number of colonies grown per gram. “Negative” or “not detected” means none were found in a set amount of sample, so also check how many grams were tested.
Singapore’s standards
Regulation 35 of Singapore’s Food Regulations provides that ready-to-eat food (food eaten as it is, without cooking or other processing) must not be imported or sold unless it complies with the microbiological standards in the Eleventh Schedule. This “ready-to-eat food” includes powdered beverages that are reconstituted with water or hot water before drinking.
Source: Singapore Statutes Online, “Food Regulations,” Eleventh Schedule https://sso.agc.gov.sg/SL/SFA1973-RG1?ProvIds=Sc11-#Sc11-
| Item | Limit (per gram) |
|---|---|
| Enterobacteriaceae (including E. coli) | Less than 10,000 CFU |
| E. coli | Less than 100 CFU |
| Bacillus cereus | Less than 200 CFU |
| Clostridium perfringens | Less than 100 CFU |
| Coagulase-positive Staphylococcus aureus | Less than 100 CFU |
| Other pathogens not in the table (such as Salmonella) | Must not be detected |
Enterobacteriaceae and coliforms cover different ranges of bacteria. If a Japanese COA reports coliforms, the result cannot be compared directly with Singapore’s limit, so ask whether the supplier can also provide an Enterobacteriaceae result. To be sure whether matcha powder is assessed in this category, check with your importer or the Singapore Food Agency (SFA).
Thailand’s standards
Thailand’s Ministry of Public Health Notification No. 416 (2020) provides that the foods listed in its table must not contain pathogens beyond the types and amounts specified, and tea is on that list. For tea, Salmonella must not be detected in 25g, and Staphylococcus aureus must not be detected in 0.1g. For products that are not heat-treated and are sealed in rigid airtight containers such as cans and stored at room temperature, S. aureus must be 100 or less per gram.
There are no limits for total plate count or for yeast and mould for plain matcha powder. For flavoured dried tea packed in sealed containers (“prepared tea” under Notification No. 196, such as latte mixes), there is a yeast and mould limit of less than 100 per gram. If you import a mix, ask for this item on the COA too. Notifications can be amended, so check the latest rules with your importer or Thai FDA before importing. The whole import process is covered in How to Import Matcha into Thailand.
How to read pesticide residues and heavy metals
Even if a COA says “complies,” if it was judged against Japanese standards, it does not necessarily meet the standards of the importing country. Place the results and the limit of quantification next to the importing country’s limits yourself.
Judgement against Japanese standards
Japan’s Food Sanitation Act sets residue limits for each pesticide and each food, and prohibits the sale and import of food that exceeds them (the positive list system). Pesticides with no individual limit are subject to a uniform limit of 0.01ppm (0.01mg per kg). “Complies” on a COA prepared for Japan is a judgement against these standards.
Comparing with the importing country’s standards
Singapore sets pesticide residue limits for tea in the Ninth Schedule of its Food Regulations, and Thailand in Ministry of Public Health notifications. In Singapore, the values of the international Codex standard apply to pesticides not in the Ninth Schedule. Thailand’s standards are covered in How to Import Matcha into Thailand. The differences between countries and how to compare them are covered in How to Buy Matcha Wholesale. For green tea imported from Japan, Indonesia requires testing for pesticide residues and other items at Japanese laboratories registered with Indonesia.
“Not detected” and heavy metals
“Not detected” for pesticide residues has no fixed meaning unless you know how many pesticides were tested and how low the method can measure. Check the number of pesticides tested and the limit of quantification (the lowest concentration that can be reported as a number). Limits for lead and other heavy metals, and how to align units, are set out country by country in Matcha Lead.
How to read radioactivity results
In Japan, matcha is assessed as a powder against the general food limit (100 becquerels of radioactive caesium per kg). Singapore and Thailand have already lifted their import restrictions on Japanese food related to the nuclear accident.
Japanese standard: 100 becquerels for matcha as a powder
According to Japan’s Consumer Affairs Agency, the limits for radioactive caesium from April 2012 are 10 becquerels per kg for drinking water, 50 for milk, 50 for infant food and 100 for general food. The drinking water category also includes tea drunk as a substitute for water. Matcha is consumed as whole leaf and is often used as an ingredient in foods such as ice cream, so unlike sencha, which is assessed as brewed tea, it is assessed against the general food limit as a powder.
Source: Ministry of the Environment, “放射線による健康影響等に関する統一的な基礎資料（令和7年度版）” (Basic information on health effects of radiation, fiscal 2025 edition, in Japanese), 8.1 https://www.env.go.jp/chemi/rhm/current/08-01-11.html
Singapore and Thailand have lifted their import restrictions
According to Japan’s Ministry of Agriculture, Forestry and Fisheries (MAFF), Singapore lifted its import restrictions on 28 May 2021, and Thailand on 1 May 2015 (except some wild animal meat). As of October 2026, the places where some restrictions remain are South Korea, China, Hong Kong, Macau and Russia. Radioactivity test documents are not required for import into Singapore or Thailand.
How to read the results
On a COA with a radioactivity field, look at the result for radioactive caesium and the limit of detection (the smallest amount at which presence or absence can be judged). If it says only “not detected” with no limit of detection, you cannot tell how low it was measured. When explaining to customers in your shop, having the limit of detection figure makes it easier to answer.
How to check a laboratory’s accreditation
Check a laboratory’s reliability by its ISO/IEC 17025 accreditation, and by whether the test item is within the scope of that accreditation. Accreditation recognises a laboratory’s testing competence. It is not proof that a product has passed.
What is ISO/IEC 17025?
ISO/IEC 17025 is the international standard for the competence of testing and calibration laboratories. In Japan, the Japan Accreditation Board (JAB) and the accreditation centre of the National Institute of Technology and Evaluation (IAJapan) accredit laboratories against this standard. IAJapan’s accreditation programme takes part in an international arrangement (ILAC/APAC MRA) under which accreditation bodies in different countries recognise each other’s accreditations.
Searching the lists of accredited bodies
On JAB’s search page for accredited conformity assessment bodies, you can search by accreditation number, scope of accreditation and standard number. If the COA or test report shows an accreditation number, search with that number. IAJapan also publishes a list of the laboratories it accredits.
Checking the scope
Accreditation has a scope, and which test items and methods are recognised differs from laboratory to laboratory. A laboratory may be accredited for pesticide residues but not for microbiology. Even if a test report carries an accreditation mark, check the list to see whether that item is within the scope.
What to request and ask your supplier
If you tell your supplier at the quotation stage which items you need and against which country’s standards, the COA arrives in a form that is easy to compare. Adding items later costs time and money for testing.
Documents to request
- A COA for the lot of your actual order (separate from the sample’s lot)
- Copies of external laboratory reports for pesticide residues, heavy metals and so on
- The specification sheet (to compare with the COA results)
- For Singapore, an Enterobacteriaceae result; for latte mixes going to Thailand, a yeast and mould result
Questions to ask
- Are the COA figures for the matcha after grinding, or for the tencha raw material?
- The laboratory’s name and its ISO/IEC 17025 accreditation number
- How many pesticides were tested, and what is the limit of quantification?
- When a result is close to a limit, how do you decide on retesting or shipping?
Documents from Omakase Matcha
Omakase Matcha sources matcha directly from the growing regions of Uji, Yame, Kagoshima, Shizuoka and Miyazaki, and accepts orders from 1kg. The differences between grades are covered in Matcha grades. We send up to 3 samples, so please request documents along with them. We also visit shops in Singapore and Thailand.
Sources
- Singapore Statutes Online, “Food Regulations,” Regulation 35 https://sso.agc.gov.sg/SL/SFA1973-RG1?ProvIds=pr35-#pr35-
- Singapore Statutes Online, “Food Regulations,” Eleventh Schedule https://sso.agc.gov.sg/SL/SFA1973-RG1?ProvIds=Sc11-#Sc11-
- Singapore Statutes Online, “Food Regulations,” Regulation 30 (pesticide residues) https://sso.agc.gov.sg/SL/SFA1973-RG1?ProvIds=pr30-#pr30-
- Thai Ministry of Public Health Notification No. 416 (B.E. 2563), microbiological (pathogen) standards (in Thai) https://exfood.fda.moph.go.th/law/data/announ_moph/P416.PDF
- Thai Ministry of Public Health Notification No. 196 (B.E. 2543), “Tea” (consolidated version published by Thai FDA, in Thai) https://food.fda.moph.go.th/media.php?id=510362387866591232&name=Compi_196.pdf
- Ministry of Education, Culture, Sports, Science and Technology, “日本食品標準成分表（八訂）増補2023年” (Standard Tables of Food Composition in Japan, Eighth Revised Edition, Supplement 2023), matcha (in Japanese) https://fooddb.mext.go.jp/details/details.pl?ITEM_NO=16_16035_7
- Consumer Affairs Agency, “食品中の残留農薬等” (Pesticide residues in food, in Japanese) https://www.caa.go.jp/policies/policy/standards_evaluation/pesticide_residues
- Ministry of Health, Labour and Welfare Notification No. 497 (uniform limit, in Japanese) https://www.caa.go.jp/policies/policy/standards_evaluation/pesticide_residues/assets/standards_cms208_240918_02.pdf
- Consumer Affairs Agency, “食品中の放射性物質の対策と現状について” (Measures against radioactive substances in food, in Japanese) https://www.caa.go.jp/policies/policy/standards_evaluation/food_pollution/criterion/assets/standards_cms105_260626_01.pdf
- Ministry of the Environment, “放射線による健康影響等に関する統一的な基礎資料（令和7年度版）” (Basic information on health effects of radiation, fiscal 2025 edition), 8.1 (in Japanese) https://www.env.go.jp/chemi/rhm/current/08-01-11.html
- MAFF, “アジアにおける規制措置の変遷” (Changes in import restrictions in Asia, in Japanese) https://www.maff.go.jp/j/export/e_shoumei/oshirase/asia.html
- MAFF, “輸出証明書の発行（放射性物質）” (Export certificates for radioactive substances, in Japanese) https://www.maff.go.jp/j/export/e_shoumei/index.html
- Indonesian Quarantine Agency Head Decree No. 2314 of 2025, Annex II (published by MAFF, in Indonesian) https://www.maff.go.jp/j/shokusan/export/attach/pdf/id_lab-26.pdf
- National Institute of Technology and Evaluation, IAJapan, “ASNITEの概要” (Overview of ASNITE, in Japanese) https://www.nite.go.jp/iajapan/asnite/outline/index.html
- National Institute of Technology and Evaluation, IAJapan, “ASNITE認定事業者一覧” (List of ASNITE accredited bodies, in Japanese) https://www.nite.go.jp/iajapan/asnite/lab/index.html
- Japan Accreditation Board, “JABに認定された適合性評価機関” (Conformity assessment bodies accredited by JAB, in Japanese) https://www.jab.or.jp/certification_institutions
- Japan Accreditation Board, “試験所・校正機関（ISO/IEC 17025）” (Testing and calibration laboratories, in Japanese) https://www.jab.or.jp/service/laboratory
