should, like all other garments worn by humans in cleanrooms, serve to protect the product or process.
about cleanroom shoes and cleanroom socks
ESD Electrostatic Discharge
Wearing so-called ESD shoes is intended to prevent disruptive discharges between the wearer and his environment. According to standard EN 61340-5-1:2016, the contact resistance should be less than 3.5 x 107 ohms.
Steel toe cap, aluminium toe cap and composite toe cap
All three variants are certified according to EN ISO 22568-1, -2, -3, -4:2019 for outside and EN ISO 20344 for inside the shoe. The composite toe cap is extremely impact resistant, highly elastic and approx. 50% lighter than the steel toe cap. The aluminium toe cap is also approx. 50% lighter than the steel toe cap.
Identification: SB [OB], S1 , S2  and S3 
These markings reflect the requirements for safety shoes and (voluntary) additional requirements according to EN ISO 20345 [occupational shoes according to EN ISO 20347].
Basic requirement: slip resistance SB, divided into 3 classes (SRA, SRB or SRC). The energy absorption of the toe cap is 200 joules.
- S1 – as SB, additional antistatic, oil and petrol resistant outsole, energy absorption in the heel area
- S2 – same as S1, additional resistance of the shoe upper against water penetration and water absorption
- S3 – like S2, additional penetration resistance and profiled outsole