Standards and Protection Classes for Safety Footwear

Safety shoes protect against workplace injuries. The protective functions they provide are defined by standards, protection classes, and additional markings. Here, you’ll learn what these designations mean and what to look for when choosing safety shoes.

What standard applies to safety shoes?

Safety shoes are tested in accordance with the EN ISO 20345 series of standards. This series specifies the basic and additional requirements for safety shoes.

The term varies depending on the level of standardization:

ISO refers to an international standard established by the International Organization for Standardization.
EN ISO refers to an ISO standard developed internationally that has been adopted as a European standard.
DIN EN ISO refers to the German adoption of this European standard.

The year indicates the respective edition of the standard. The current German edition is DIN EN ISO 20345:2024-06. It incorporates EN ISO 20345:2022, including Amendment A1:2024.

Older safety shoes may still be labeled according to earlier editions, such as DIN EN ISO 20345:2011. Since requirements and labeling have changed, the protection classes of different generations of standards must not be compared with one another without verification.

What is a protection class?

The protection class describes a specified combination of protection requirements that safety footwear must meet.

All safety shoes that comply with EN ISO 20345 are equipped with a toe cap that can withstand an impact energy of 200 joules. Depending on the protection class, additional features may be included, such as antistatic properties, water resistance, or puncture resistance.

The appropriate protection class depends on the hazards present at the specific workplace.

Model BRANDON S7S FO LG SR ESD

Protection Classes: Essential Requirements and Additional Requirements

Basic Requirements are characteristics that make a protection class must . They determine the scope of protection for the shoe as defined by the standard.

Additional Requirements are additional features that may be available depending on the model. They can enhance protection, comfort, or suitability for specific applications. They, too, may be tested in accordance with standards and identified by their own markings.

Good to know: Not every additional requirement is automatically included in a protection class. The relevant factors are the edition of the standard and the marking on the specific shoe.

Overview of Protection Classes

The following table shows the protection classes according to DIN EN ISO 20345:2024-06. It provides a simplified summary of the essential requirements.

Key: ✓ = required · – = not required by this protection class

Protection Class	Closed heel area	Antistatic	Energy absorption Heel	Water Penetration and Water Absorption (WPA)	Passage inhibition	Tread	Water Resistance (WR)
SB	–	–	–	–	–	–	–
S1	✓	✓	✓	–	–	–	–
S1P	✓	✓	✓	–	Metal (P)	–	–
S1PL	✓	✓	✓	–	Non-metal (PL)	–	–
S1PS	✓	✓	✓	–	Non-metal (PS)	–	–
S2	✓	✓	✓	✓	–	–	–
S3	✓	✓	✓	✓	Metal (P)	✓	–
S3L	✓	✓	✓	✓	Non-metal (PL)	✓	–
S3S	✓	✓	✓	✓	Non-metal (PS)	✓	–
S4	✓*	✓	✓	–	–	✓*	–
S5	✓*	✓	✓	–	Metal (P)	✓	–
S5L	✓*	✓	✓	–	Non-metal (PL)	✓	–
S5S	✓*	✓	✓	–	Non-metal (PS)	✓	–
S6	✓	✓	✓	✓	–	–	✓
S7	✓	✓	✓	✓	Metal (P)	✓	✓
S7L	✓	✓	✓	✓	Non-metal (PL)	✓	✓
S7S	✓	✓	✓	✓	Non-metal (PS)	✓	✓

*See the explanations below regarding S4 and S5

Note: This table is a simplified editorial summary. It does not replace the complete normative requirements.

What do these differences mean?

S1: Basic protection with a closed heel area, antistatic properties, and energy absorption in the heel area.
S1P, S1PL, and S1PS: Same as S1, but with additional penetration resistance.
S2: Same as S1, with additional requirements regarding water permeability and water absorption of the outer material.
S3, S3L, and S3S: Same as S2, but with added puncture resistance and a treaded outsole.
S4 and S5: Class II safety shoes made of rubber or polymer materials. The S5 designation adds puncture resistance and a treaded outsole.
S6: Class I safety shoe that meets the S2 requirements and is additionally waterproof throughout the entire shoe.
S7, S7L, and S7S: Same as the S3, S3L, and S3S, respectively, but with the entire shoe being waterproof.

Close-up of a Baak shoe with two hands pulling on a rubber strap

Model SORAN S1PS CI FO HRO SR ESD

A man's legs, clad in safety shoes, are standing on a large rock on the beach

Model PEGASUS S3S FO HRO SR ESD

A man's legs, clad in black Baak safety boots, walk through the woods

Model MAV S7S CI FO SR ESD

Supplementary Labeling Explained Simply

In addition to the protection class, other markings provide information about which additional requirements a safety shoe meets.

Labeling	Meaning
A	Antistatic
ON	Ankle protection
C	Conductivity
CI	Thermal Insulation of the Base Complex
CR	Cut protection
E	Energy absorption in the heel area
FO	Resistance of the outsole to fuel
HI	Thermal Insulation of the Base Complex
HRO	Heat resistance of the outsole when exposed to contact heat
LG	Suitability for use on ladders
M	Metatarsal protection
P	Metal Penetration Resistance
PL	Non-metallic puncture resistance, tested with a 4.5-mm test nail
P.S.	Non-metallic puncture resistance, tested with a 3.0-mm test spike
SC	Abrasion Resistance of a Cap
SR	Additional Slip Resistance Test
EPA	Water Penetration and Water Absorption
WR	Water resistance of the entire shoe

Not all additional labels are available or appropriate for every protection class. The key factor is which hazards actually occur in the workplace.

Fourteen circular icons, with the abbreviations for all the features explained earlier listed below them

Which safety shoe is the right one?

The appropriate protection class is determined based on the workplace risk assessment. In addition to the protection class, factors such as the risk of slipping, moisture, sharp objects, temperatures, and ergonomic requirements also play a role.

Our Tip: When purchasing, make sure the shoe is fully labeled and choose the level of protection that matches your specific application. If you have any questions, consult your occupational safety specialist or your employer.