How to Choose Safety Shoes: SB, S1, S2, S3 Grades and 4 Stages of Selection

Check first that the marking passes, then match the site with three questions: if you need antistatic, choose from S1 up; if the floor is often wet, look from S2 up; puncture resistance is needed when sharp objects may be on the floor. A higher grade is not the same as better — what the higher grade adds is functions your site may never use.

This article breaks shoe selection into 4 stages:

• Stage 1 | Marking: read the grade marking on the shoe and the commodity inspection mark, and both must match.

• Stage 2 | Grade: what SB, S1, S2, and S3 each add, in one table.

• Stage 3 | Site: three questions — antistatic, waterproofing, puncture resistance — matched against electronics plants and warehousing.

• Stage 4 | Toe cap, size, and replacement: what material the toe cap is, how to match sizes, and when to replace.

For why a static-controlled site should start from the shoes, see Why do engineers say “start with the shoes” when pushing for plant-wide ESD improvement? This article starts from “shoe grades and purchasing.” Each stage below covers: what to do, what the public sources say, and what Jiahon can help with; sources, exceptions, and our own compilation are in the “Notes” at the end.

Figure 1: The four stages of safety shoe selection: marking, grade, site, and toe cap / size / replacement (illustration, not to scale; matching grades: antistatic from S1, water penetration resistance from S2, puncture resistance at S3, and the European standard also has S1P).

Stage 1: Marking — first confirm it passes

What to do:

• Look at the grade marking on the shoe or the packaging (SB, S1, S2, S3); it tells which items the pair has passed.

• Look at the commodity inspection mark.

• When buying several models, check each model’s marking against its specification; do not look at just one sample model.

What the public sources say:

Taiwan’s safety shoe standard is CNS 20345, overseen by the Bureau of Standards, Metrology and Inspection, Ministry of Economic Affairs (BSMI below). BSMI’s Kaohsiung Branch website published the test results for “Safety Shoes on the Market”: sampled for impact resistance and compression resistance under CNS 20345, all results conformed; but in the marking check, for 1 item the information or form of the commodity inspection mark on the market-bought sample did not match the initially submitted specification; the appendix calls on consumers to buy safety shoes bearing the commodity inspection mark (Note Table 1). The toe cap test and the marking check are two separately checked matters: a conforming sample test does not mean the marking can be skipped (our own compilation).

What Jiahon can help with:

The product page text of the three shoes on the site (see Stage 3) does not state the grade (SB, S1, S2, S3), CNS 20345, or a commodity inspection mark. When you inquire, ask clearly, and check the marking on the shoe when it arrives. Of these, the product page of the Anti-Static Short-Cut Plastic-Steel Shoes says “anti-static test report available.”

Stage 2: Grade — how SB, S1, S2, and S3 differ

What to do: All four grades share one “basic requirement” as the base, that is, the impact and compression tests of the toe cap; each grade going up adds one more group of items:

What the public sources say:

The table above is compiled from the BSMI presentation “CNS 20345 Marking Classification”. The presentation also mentions that the old standard CNS 8878 listed antistatic as mandatory, while CNS 20345 lists it as an additional item, so SB carries no assurance of antistatic. The European standard has one more grade, S1P, which is S1 plus puncture resistance (Note Table 2).

What Jiahon can help with:

The product page text of the three shoes on the site does not mark SB, S1, S2, or S3; which grade each corresponds to, please inquire. Tell us the answers to the three questions in Stage 3, and we can first rule out the models whose grade is not enough.

Stage 3: Site — three questions to converge on the grade

What to do: Answer three questions in turn:

If all three answers are “no,” put the emphasis on light weight and comfort, and there is no need to trade anything off for functions you will not use. The third question is a site risk assessment; it should be answered by the site supervisor (our own compilation).

Practice at two common kinds of site:

• Electronics plants and static-controlled areas: what is wanted is usually shoes that can be worn all day without tiring, with an antistatic function, so SB will not be the starting point. The “antistatic” in the standard is the performance of the shoe itself; static control manages the whole conductive path — see the further reading.

• Warehousing and logistics: first ask where the risk of falling objects is, and whether the floor is often wet. Toe cap crush protection is a basic requirement of every grade; where the floor is often wet, water penetration resistance from S2 up is a plus; the European standard’s description is that every grade undergoes a slip test, and S3 also has a cleated outsole.

What the public sources say:

The European standard retailer’s description writes that the upper material of S2 resists penetration for at least 60 minutes (Note Table 2); the puncture resistance that S3 adds over S2 is also listed in the BSMI presentation’s classification table. We did not find a public provision of CNS 20345 on the puncture test value, so no figure is written.

What Jiahon can help with:

• Anti-Static Plastic-Steel Shoes: the product page states an anti-static sole design and a water-repellent upper; whether it has passed tests for water penetration and absorption resistance (S2 up) or puncture resistance, the product page does not state; please inquire.

• Anti-Static Short-Cut Plastic-Steel Shoes: the product page states anti-static EVA added in the midsole, a dual-density polyurethane (PU) slip-resistant, wear-resistant outsole, and a leather upper, with an anti-static test report available; water penetration and puncture resistance are not stated on the product page; please inquire.

• Steel-Toe Safety Shoe Series: the product page states that the whole series has steel toe caps, anti-static soles, oil-resistant slip-resistant outsoles, and waterproof edge binding; models with the suffix SP also have a steel midsole for puncture resistance. This is the series’ own model description; whether it corresponds one-to-one with S3 and S1P of the standard, please inquire. Sites where the answer to the third question of Stage 3 is “yes” can start with this series.

Stage 4: Toe cap, size, and replacement

What to do:

• Toe cap material: steel toe or plastic-steel toe (composite) is a choice of model, not a grade; the toe caps of all four grades must pass the same test.

• Size: the standard sets toe cap dimensions by shoe size, so both large and small foot shapes must be matched. Before purchase, have each site pick representative wearers to try on, taking foot shape and working posture together.

• Replacement: BSMI’s material gives no service life, and this article gives no fixed figure either. Have the site supervisor set an inspection method, regularly checking sole wear, toe cap deformation, water entry, and whether the marking is still legible; replace if it does not pass (our own compilation).

What the public sources say:

The toe cap dimensions given in the BSMI presentation vary with shoe size: the lower limit of the toe cap’s internal length runs from 34 mm for size 36 and below to 42 mm for size 45 and above; the internal clearance after impact runs from 12.5 mm to 15.0 mm (Note Table 3). A public description from a U.S. shoe maker (Thorogood) writes that composite toe caps are lighter than steel and conduct heat poorly; steel conducts electricity and heat and triggers an alarm passing a metal detector, while composite more easily passes if there is no steel shank inside the shoe (Note Table 4).

What Jiahon can help with:

• Anti-Static Plastic-Steel Shoes: a non-metal plastic-steel toe cap; the product page states more than 20% lighter than traditional iron-toe shoes, with a widened toe cap; sizes 35 to 45, unisex. The notes for use on the product page say “if the toe cap is clearly deformed, please replace with new shoes.” Actual weight and thermal conduction data are not stated; please inquire.

• Anti-Static Short-Cut Plastic-Steel Shoes: plastic-steel toe, short cut; four colors — white, black, gray, blue — sizes 34 to 50, same style for men and women.

• Steel-Toe Safety Shoe Series: steel toe, with an imported leather upper and a wide last; the sizes are not stated on the product page; please inquire. Steel conducts electricity and heat and triggers an alarm passing a metal detector (Note Table 4); if the site has metal detection, check this point first.

For teams with widely varying foot shapes, models with a wider size range (the short-cut model at sizes 34 to 50, the other at 35 to 45) make it easier to buy everything in one purchase.

Shoes are just a part of site protection. Gloves, protective gear, and other wear should be planned together; see What does the MIT halo overlook? A guide to choosing cleanroom wear: cleanroom suits, cleanroom shoes, and static slippers.

Further reading

To read through the related process steps together, continue with these:

• Why do engineers say “start with the shoes” when pushing for plant-wide ESD improvement?: why static control starts with the shoes

• Electronics industry rethinks the human conductive path of “wrist strap and shoes”: how to manage the whole conductive path

• What does the MIT halo overlook? A guide to choosing cleanroom wear: cleanroom suits, cleanroom shoes, and static slippers: how to choose wear other than shoes

To match grade and model, please first prepare three items: the main risks at the site (falling objects, sharp objects, water, or static control); the number of people and the size range needed; and the current models in use.

Further reading: What is the difference between safety shoes and ESD shoes?

Notes: sources and exceptions

This is for people who need to check; skipping it does not affect the method above. Where your customer’s requirements, the site’s safety rules, and the shoe maker’s written specifications differ from this article, go by those.

Where each stage comes from

Note Table 1 | BSMI Kaohsiung Branch sampling of “Safety Shoes on the Market”

The file upload date is about March 2026 (converted from the file number; the appendix itself has no date and does not state the number of samples).

Note Table 2 | Where the grades come from

Note Table 3 | Toe cap dimensions by shoe size

For the values for sizes between the two ends, see the BSMI presentation (Source 2).

Note Table 4 | Toe cap material

Source: Source 5.

Standards cited

The standards cited in this article should be taken in the current edition of each issuing body.

• CNS 20345, Safety Footwear (BSMI presentation: CNS 20345 explanation). Issuing body: Bureau of Standards, Metrology and Inspection, Ministry of Economic Affairs.

• Appendix of test results, “Safety Shoes on the Market” (sampled under CNS 20345). Issuing body: Kaohsiung Branch, Bureau of Standards, Metrology and Inspection.

• ISO 20345, Personal protective equipment — Safety footwear. Issuing body: ISO (International Organization for Standardization).

This is the general case; individual cases still have to be judged on their own.

Exceptions and limits

What we saw and what we did not see: What this article read is the BSMI Kaohsiung Branch’s sampling appendix, BSMI’s CNS 20345 presentation, two European retail or information pages, and a public description from a U.S. shoe maker; we did not read the full text of CNS 20345 or ISO 20345. The grade table and toe cap dimensions come from the presentation; S1P and the 60 minutes come from the retail pages, not from the standards’ own text.

Content removed: the puncture test value was seen on just one public online encyclopedia page, with no second source, so this article does not write it.

Editions and dates: the BSMI presentation says CNS 20345 was published in January 2015, based on the second edition of ISO 20345 issued in 2011, and the marking requirement is written as CNS 20345:2015; Source 4 says EN ISO 20345:2022 added two grades, S6 and S7; this article did not read the contents of the 2022 edition, and did not find any revision announcement for CNS 20345 since, so the grade table is compiled on the older edition; before purchase, go by the current edition announced by BSMI. The two BSMI files carry no date, and their upload dates were converted from the file numbers; the European retailer’s page has no date, and the U.S. shoe maker’s description is April 2023.

Sources with a stake: the descriptions by retailers and shoe makers have a sales stake.

Our own compilation: the following were compiled by this article from the sources, and the sources do not write them this way: “a conforming sample test does not mean the marking can be skipped” is a summary that looks at the sampling result and the marking check separately; “three questions to converge on the grade” and “if all three answers are no, put the emphasis on light weight and comfort” are methods summarized from the grade table, not the standard’s selection procedure, and leaving the third question to the site supervisor is also this article’s suggestion; the inspection items for replacement are this article’s suggestion, and the sources give no service life.

Scope: this article does not cover puncture test values, comparison of standards among countries, shoes for special uses (for example electricians’ shoes and heat-resistant shoes), prices, or delivery times.

Equipment and products: the figures and statements under “What Jiahon can help with” are the text read from the product pages on October 13, 2026; we did not look at product pictures, and they were not verified by this article; specifications are as on each product page, and for grades, weights, and specifications not stated on a product page, please inquire.

This article is a summary of the general case. It is not a restatement of standard clauses, nor an endorsement of any one supplier, shoe maker, or service provider, nor an assurance of safety at your site. Go by your customer’s specifications, the site’s safety rules, the shoe maker’s written specifications, and your own try-on and verification; this is the general case, and individual cases still have to be judged on their own.