When a customer says "attach an SGS report", that sentence can refer to at least three different documents. Sending the wrong one not only wastes money but also adds a two-week detour to the lead time, and most of the time the problem is that the test request form did not state the test method clearly.
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What each of the four documents proves
Let us get the terms aligned first. The four documents commonly requested in the electronics supply chain prove completely different things:
| Document | What it proves | Who issues it |
|---|---|---|
| ESD test report | The surface resistance and static decay performance of the material meet a specific grade | Third-party laboratory |
| RoHS report | The 10 restricted hazardous substances are absent or below the limits | Third-party laboratory |
| REACH report | No substances of very high concern (SVHC) are present, or they have been notified as required | Third-party laboratory |
| SDS safety data sheet | Safe handling, hazard identification and regulatory information for the product | Prepared by the manufacturer (can be verified by a third party) |
In practice, the "SGS report" customers talk about mostly means the RoHS / REACH pair, because SGS is one of the testing bodies most often specified in Taiwan. But ESD testing is another matter, and the two cannot stand in for each other.
The most common mistake in ESD testing: not specifying the test method
This is the most important section of this article, because the waste it causes is the most direct.
Brushes, mats and gloves are all planar materials, and the dedicated test method for their surface resistance is ANSI/ESD STM11.11 (Surface Resistance Measurement of Planar Materials), established by the EOS/ESD Association.
If the test request form does not specify a method, the laboratory may mistakenly apply an electrostatic discharge test method for the IC component level, such as HBM / MM / CDM. Those methods measure how much a component can withstand, not the surface resistance of a material. The report you get back is not technically wrong, but it does not answer the customer's question at all, and the only option is to submit again. The cost of this mistake is not the test fee; it is the two extra weeks of lead time.
The test request form should state four things explicitly:
| Field | What to fill in |
|---|---|
| Test method | ANSI/ESD STM11.11 (the latest version at the time) |
| Test item | Surface Resistance |
| Test object | The filament section and the handle section tested separately, with a separate value for each |
| Expected grade | Static dissipative (10⁴ Ω or more and less than 10¹¹ Ω) or conductive (less than 10⁴ Ω); if the customer specifies its own range (such as the 10⁶–10⁹ Ω common in practice), write that instead |
The third item is especially easy to miss. The filament and the handle are different materials with different resistance, and a number measured on the two together means nothing, while a complete ESD path needs both to meet the requirement. Only with a report that gives separate values can the customer's quality assurance department check item by item.
Another benefit that is rarely mentioned: a quality assurance engineer who knows the subject will rate a supplier's professionalism differently on seeing a report that cites STM11.11 instead of a generic "ESD test". It is a detail that costs nothing but affects trust.
How the scope of RoHS and REACH differs
The two are often mentioned side by side, but their scope differs greatly.
RoHS restricts 10 specific hazardous substances in electrical and electronic equipment, with concentration limits and material-specific exemptions; REACH regulates the chemicals in almost all products on the EU market, and its Candidate List of substances of very high concern (SVHC) already exceeds 250 entries (SDS Manager).
The criteria for identifying an SVHC include carcinogenicity, mutagenicity and reproductive toxicity (category 1A or 1B), as well as persistent, bioaccumulative and toxic substances, or substances raising similar concerns such as endocrine disruptors (REACH Regulation, Article 57).
The practical meaning for products such as brushes is: both have to be screened; doing only one side is not enough. An electronic product is electrical and electronic equipment under RoHS and an article under REACH, and both sets of rules apply at the same time. When asking for a material declaration, require it to cover the 10 RoHS substances and the REACH SVHCs.
An SDS is not a test report; it is the manufacturer's responsibility document
An SDS safety data sheet follows a fixed 16-section format. It is prepared by the manufacturer and describes the hazard identification, composition, safe handling and regulatory information of the product.
Purely solid articles are usually low in hazard, and the content of the SDS can mostly be compiled from the upstream raw material supplier's data. But two sections deserve particular attention (LCSC):
- Composition / ingredients: lists chemical names, CAS numbers and concentrations, which can be checked against the RoHS restricted substances.
- Regulatory information: states the applicable regulatory status.
An SDS also has a version issue. When you receive the document, confirm the revision date and check it regularly against the current version published by the supplier. An SDS from three years ago may not be accepted in an audit.
A declaration and a test report do not carry the same weight
This point directly affects the lead time, yet it is often skipped at the quotation stage.
| Type | Issued by | Weight | Time to obtain |
|---|---|---|---|
| Raw material supplier declaration | Upstream raw material supplier | Self-declaration within the supply chain | Available immediately for an existing material source |
| Third-party test report | Accredited laboratory | Independent verification, highly accepted in audits | Requires testing; several weeks |
Which one the customer wants has to be asked before quoting. If an existing material source is used and the customer accepts the raw material supplier's declaration, the documents can be provided almost immediately; if the customer requires a third-party report, or a new material is to be introduced, testing has to be done again.
This is also one of the reasons why, when we assess a solution, we first confirm whether an existing material source can meet the requirement. A new material may have better physical properties, but the time for new testing is often longer than tooling. If the customer's project schedule is already tight, this choice directly decides whether the project is viable.
Choosing a laboratory by customer type
Our practice is to ask the customer first "who is this report for". Whether it is for the quality assurance staff of a Taiwanese electronics company, for a European buyer, or for getting onto the customer's approved supplier list, a different body suits each of the three. This question works better than asking directly "which lab do you want it sent to", because the customer is often only passing on a requirement from further upstream.
Not every laboratory suits every requirement. The logic we use in practice to sort them:
| Customer type / requirement | Direction to choose | Reason |
|---|---|---|
| General electronics, modules, PCBA | A large testing body commonly used by industry in Taiwan | Highly accepted in audits; several documents can be completed in one place |
| European customers or exports to Europe | A European certification body | Better recognized by European brands |
| Customer has already specified a laboratory | As specified by the customer | Avoids the report being rejected and redone |
| ESD at the IC component level (HBM / MM / CDM) | A laboratory specializing in semiconductors | A different field of testing from material surface resistance |
| Surface resistance of planar materials such as brushes | A body that accepts STM11.11 | You must confirm that the body accepts this method |
The last row is worth confirming by phone first. Not every laboratory routinely accepts STM11.11 testing of planar materials, and asking in advance saves a round trip.
What these reports cannot prove
We have had a customer bring a report from two years earlier and ask to keep using it, when the raw material batch had been changed once in the meantime. In the audit the document was questioned about batch correspondence, and in the end it had to be submitted again. The boundaries of a report are narrower than most people think, and the following three points are worth making clear first:
- A report covers only the batch and the part number that were submitted. A change of material, a change of supplier, or even a different batch of the same part number is, strictly speaking, outside the scope of the original report. Being questioned about batch correspondence in a customer audit is a common situation.
- An ESD report proves the material, not the result on site. Passing on surface resistance does not mean the static problem on site will be solved: the complete dissipation path also includes the handle, the operator, the wrist strap and the grounding system.
- RoHS / REACH do not cover every customer requirement. Semiconductor and medical customers may additionally require metal ion extraction or outgassing tests. These two items are outside the standard scope of hazardous substances and have to be arranged separately.
FAQ
The customer asks for an "SGS report". What should I submit?
First confirm which kind is wanted. In practice it mostly means RoHS / REACH hazardous substance testing, but it can also mean an ESD surface resistance test. These are different tests and different reports. We suggest asking the customer directly what the report is for and which specification it will be checked against, to avoid submitting the wrong one.
Why does ESD testing have to specify STM11.11 in particular?
Because a brush is a planar material, and there is a dedicated test method for its surface resistance (ANSI/ESD STM11.11). If it is not specified, the laboratory may mistakenly apply methods for the IC component level such as HBM / MM / CDM. Those measure how much a component can withstand and cannot answer the question of material surface resistance, so the report is wasted.
Should the filament and the handle be tested separately?
Yes. They are different materials with different resistance, and a number measured on the two together means nothing. A complete ESD path needs both the filament and the handle to meet the requirement, and only with separate values can the customer's quality assurance department check item by item. Separate testing is usually charged separately, but what it saves is the time of a retest.
Can a raw material supplier's declaration replace a third-party report?
It depends on whether the customer accepts it. A declaration is a self-declaration within the supply chain, while a third-party report is independent verification and is more readily accepted in audits. If the customer accepts a declaration and an existing material source is used, the documents can be provided almost immediately; if a third-party report is required or a new material is introduced, testing has to be done again, and that often takes longer than tooling.
How long can a report be used?
A report covers the batch and the part number that were submitted. A change of material, a change of supplier or a different batch is, strictly speaking, outside the scope of the original report. An SDS also has a version issue: confirm the revision date and check it regularly against the supplier's current version.
References
- SDS Manager - RoHS and REACH Compliance Differences
- LCSC - What is a Safety Data Sheet and Why It Matters for Electronic Components
- EOS/ESD Association
- REACH Regulation (EC) 1907/2006, consolidated version
Further reading
- How to choose anti-static brush resistance: a three-grade selection guide
- Compounded or surface-coated conductive fiber? Service life and selection explained
- What to prepare for a custom brush quote: the three spec elements
- How to choose cleanroom brushes: 3 red lines where the class decides the material
- The complete guide to custom brushes
- The complete guide to brush materials
- Factory acceptance for brush shedding: what the three-stroke finger-comb test and the pull test each check
