The Meaning of EN ISO 20345:2022 and S1, S3, and S7 Safety Shoes.

Anyone who works professionally with personal protective equipment (PPE) knows that safety shoes are not a “one-size-fits-all” product. The right choice depends on workplace risks, the surface, weather conditions, the type of work, and legal requirements. In Europe, EN ISO 20345:2022 is the basic standard for safety shoes. In the Netherlands, your policy must also comply with the Working Conditions Act, the Working Conditions Decree, and the mandatory RI&E (Risk Inventory & Evaluation).

In this article, we clearly explain what EN ISO 20345 entails, the difference between S1, S3, and S7, and how you can practically apply these classifications to select the right footwear for your employees. For the legal context regarding PPE obligations, you can consult the official information from the Dutch government via Arboportaal (PPE). For an explanation of the RI&E, Arboportaal (RI&E) is a logical place to start.

What is EN ISO 20345?

EN ISO 20345 is the standard that establishes minimum requirements for safety footwear. This standard applies to footwear designed to protect the wearer from common workplace hazards, such as impacts, falling objects, slips, sharp objects on the ground, and, in certain cases, moisture or cold. An essential component of EN ISO 20345 is the mandatory safety toe cap with impact protection. In practice, this means that shoes meeting this standard have a safety toe cap capable of withstanding an impact energy of 200 joules.

In addition to the safety toe cap, the standard includes additional requirements and optional features that depend on the type of shoe and the selected classification. These include slip resistance, energy absorption in the heel, and, in some classes, puncture resistance and water resistance. 

Note for procurement practices: standards (such as EN ISO 20345) are in many cases available only for a fee through standardization bodies. For the European context regarding product safety and CE marking (which includes PPE), the European Commission is an authoritative source: European Commission – CE marking.

Legal framework: why PPE and safety shoes are not “optional”

Safety shoes are PPE. Employers must first address risks at the source and implement collective measures; if risks persist, PPE (such as safety shoes) is mandatory. This follows from the Dutch occupational health and safety framework. A practical, official explanation can be found on Arboportaal.

In practice, this means: your RI&E determines whether and what type of safety footwear is required for each position or task. The RI&E also serves as the starting point for fit testing, selecting the right fit, and establishing PPE policy. See Arboportaal – RI&E for more information.

How do you interpret the classifications of safety shoes?

The letter S stands for “Safety.” The number that follows refers to a set of minimum requirements. Important to know: a higher class is not automatically “better” in all situations, but it does offer more comprehensive protection. Additional features can also have drawbacks, such as increased weight, reduced ventilation, or less flexibility. A warehouse worker in a dry environment typically doesn’t benefit from a heavy, water-resistant outdoor shoe, whereas a construction site specifically requires durability, traction, and protection against penetration.

In addition, safety shoes are often marked with additional symbols indicating specific features, such as antistatic properties, slip resistance, or waterproofing. It is therefore wise to always check the entire label and not just the S class. Comfort and fit also play a role here: many jobs that involve a lot of standing and walking place physical strain on the body, and a well-fitting, ventilated shoe can help prevent discomfort. For a practical overview of physical strain in the workplace, this official source is helpful: Arboportaal – Physical Strain. 

Safety Shoe Classifications: S1, S3, and S7

The classes listed below are commonly encountered in procurement processes and PPE policies. We’ll explain them along with their characteristics, applications, and key considerations, so you can more easily translate standards into practical application.

S1 Safety Footwear: For Dry Indoor Environments

S1 safety shoes are designed for workplaces where the floor is generally dry and where there is no structural exposure to water or mud. Examples include logistics, assembly, light industry, and technical services in a manufacturing environment.

• Safety toe cap: Basic protection against impacts and falling objects in accordance with EN ISO 20345.

• Antistatic properties: Reduces the buildup of static electricity in normal work environments.

• Energy absorption in the heel: Contributes to comfort and reduces impact stress when walking and standing.

• Closed heel: Supports stability and fit.

Practical tip: S1 is often a good choice when comfort and breathability are important, such as when walking long distances. Please note: S1 generally does not offer protection against water penetration or standard puncture resistance. If there is a risk of nails, shards, or metal debris on the floor, a higher class is generally more appropriate.

For repetitive walking and standing work, consider incorporating broader ergonomic factors as well. Arboportaal offers additional guidance on physical strain: Arboportaal – physical strain.

S3 Safety Shoes: For Outdoor Work and Harsh Conditions

S3 is one of the most commonly chosen safety classes for construction, installation, infrastructure, agricultural environments, and heavy industry. The main reason: S3 combines basic requirements with puncture resistance and protection against water penetration. This makes it a true all-rounder for varying conditions. 

• Water-repellent or water-resistant upper material: Helps keep feet drier on wet grass, in the rain, and on damp surfaces.

• Puncture resistance: Protects against sharp objects that could penetrate the sole from below.

• Treaded sole: Provides extra traction on unpaved or dirty surfaces.

• Anti-slip properties: Important on wet, slippery, or dirty floors.

Practical tip: S3 is often chosen as the “standard” for field work, but check whether the job actually involves a penetration risk. Penetration resistance is essential on construction sites, but may be less relevant in, for example, a fully controlled production environment. It’s also wise to consider the type of puncture protection and the sole construction, especially if the work involves a lot of kneeling or working on uneven terrain.

Because slip and fall risks outdoors vary greatly depending on the surface, it helps to base your choice on your Risk Inventory and Evaluation (RI&E) as well as on structural measures to prevent falls. See also the official explanation regarding foot protection: Arboportaal – Foot Protection (work shoes).` 

S7 Safety Shoes: For Demanding Conditions and Wet Environments

S7 is a relatively new and more rigorous classification within EN ISO 20345. This class was developed for situations where water resistance and durability are crucial. In practice, we are seeing S7 more and more frequently in sectors where people work outdoors for extended periods, in wet conditions, or in environments where the shoe is structurally exposed to water.

• Waterproof construction: Designed to keep the foot dry during prolonged exposure to wet conditions.

• Puncture resistance: Protection against sharp objects from below.

• Distinctive tread pattern and traction: For muddy, wet, or variable terrain.

• Stability and support: Often built more robustly for intensive use.

Important: S7 is not the same as electrical insulation. Electrical risks require specific standards and choices depending on the hazard (for example, ESD to control electrostatic discharge or, conversely, insulating properties for work on electrical installations). Let the RI&E guide your decisions and select footwear accordingly. S7 is particularly relevant when waterproofing, durability, and off-road performance are key considerations.

Do you deal with electrical hazards or static electricity in the workplace? Document this explicitly in the RI&E and, if necessary, include specialized PPE requirements. Arboportaal provides thematic information on safe and healthy working practices and helps you structure your obligations through the RI&E: Arboportaal – RI&E.

Why Compliance with EN ISO 20345 Makes a Difference in Practice

Compliance with EN ISO 20345 is not just a paperwork exercise. It is a direct application of risk management in the workplace. Employers are required to provide appropriate PPE when risks cannot be eliminated by other means. This includes selecting safety shoes that are appropriate for the hazards, working conditions, and the nature of the work. A concise, official explanation of PPE obligations can be found on the Arboportaal website under “Personal Protective Equipment.”

Choosing the wrong shoes not only leads to a higher risk of injury but often also to comfort issues, fatigue, and a reduced willingness to wear them. An employee who finds the shoes too heavy, too hot, or too stiff is more likely to look for “alternatives.” That’s why it’s wise to base purchasing decisions not only on standards but also on fit, weight, breathability, sole construction, and the wearer’s work pattern.

How to Choose Between S1, S3, and S7

Use these practical guidelines as a starting point (and always back them up with the RI&E):

• Choose S1 for dry indoor locations with no inherent risk of water, mud, or sharp objects on the floor. Ideal when comfort and ventilation are priorities.

• Choose S3 for outdoor work, wet or contaminated surfaces, and locations where there is a realistic risk of penetration, such as construction sites and areas with debris or metal scraps.

• Choose S7 when waterproofing and heavy-duty use are key, and workers are exposed to wet conditions for extended periods, requiring robust traction and protection.

Not sure which one to choose? Then it’s wise to assess the work environment for each specific job, possibly through a trial period. This prevents a general, standard choice from falling short in practice. Preferably, document the results in your PPE policy and link them to the RI&E. 

Conclusion: Knowledge of standards accelerates better PPE choices

EN ISO 20345 provides a reliable foundation for selecting safety footwear, but the real benefit lies in applying these standards to the workplace. S1, S3, and S7 each have their own specific applications and enable targeted selection based on risks, comfort, and durability. By combining standards with practical input from users and a clear RI&E, you increase both safety and willingness to wear PPE.

Practical next step (CTA): Have your footwear selection reviewed against the RI&E

• Do you want to be sure that your choice aligns with your legal obligations? Use the official information available via Arboportaal – PPE.

• Looking for safety shoes that suit your industry and working conditions? Visit AllSafety.com for a wide range of safety shoes compliant with EN ISO 20345.

• Need help translating risks into the correct class (S1/S3/S7), setting up a wear test, or standardizing PPE by job function? Contact our team for expert support and a solution that works in practice.