There are different standards - the following being relevant:
 
EN ISO 20344 Test methods
EN ISO 20345 Safety shoes
EN ISO 20346 Protective shoes
EN ISO 20347 Professional shoes
 
Safety shoes for commercial use
Shoes with security features to protect their wearers from injuries which may occur in accidents in working areas, which the shoes are intended for; with toe-protection cap which protection effect against mechanical influence is tested with a test energy of 200 J.
 
Basic requirements for safety shoes are ruled by the test method DIN EN ISO 20344 which provides information about the following features and values:
 
Shape
Height of the upper part of the shoe, heel area: Shape A - low shoe, shape B - low boot, shape C - ankle boot, shape D - high boot, shape E - thigh high boot
 
Shoes in assembled form
Sole assembly: structure, separating force between upper and outer sole
Toe protection: General information, toe cap length, resistance to impact, resistance to pressure, corrosion resistance of toe caps in metal, density, slip resistance

Upper
Thickness, tear strength, resistance, bending behaviour, pH value, water vapour permeability, water vapour value, hydrolysis, chromium (VI) content

Vamp and quarter lining
tear strength, abrasion resistance, water vapour permeability and water vapour value, pH value, chromium (VI) content

Tongue
tear strength, pH value, chromium (VI) content

Insole
thickness, pH value, water absorption and water release, abrasion resistance

Outer sole
thickness, tear strength, abrasion resistance, bending behaviour, hydrolysis, separating force between the layers of multilayer soles
 
CLASSIFICATION I & II:
I. Shoes in leather or other materials, except any rubber or polymere material
II. All rubber and polymere materials
 
 
SB – Basic requirements, can be classification I & II
S1 – Additional requirements (A+FO+E), must be classification I
S1P – Additional requirements (A+FO+E+P), must be classification I
S2 – like S1, in addition partial watertightness (A+FO+E+WRU), must be classification I
S3 – like S2 and in addition puncture proof (A+FO+E+WRU+P), must be classification I
S4 – like S1, but as watertight boot, must be classification II
S5 – like S4, in addition puncture proof, must be classification II

Additional information/additional tests:

A – antistatic shoes
C – Conductive shoes
E – Energy absorption in the heel area
P – Puncture resistance
CI – Cold Insulation
HI – Heat Insulation
FO – oil and fuel resistant sole
HRO – Reaction on contact heat
SRA – Slip resistance (test method: ceramic tile/detergent)
SRB – Slip resistance (test method: steel floor/glycerol)
SRB – Slip resistance (test method: SRA and SRB passed)
WR – Resistance of the whole shoe to water penetration and absorption
WRU – Resistance of the upper to water penetration and absorption
 
Tested according to the basic requirements and the following additional requirements:
(HI) Heat insulation
(CI) Cold insulation
(HRO) Contact heat resistance
(SRC) – Slip resistance (test method: SRA and SRB passed)
(FO) – Oil and fuel resistant sole
(S3) Closed heel area, antistatic, energy absorption capacity in the heel area, water penetration and absorption, puncture resistance, treaded outer sole
 
LABELLING 
Each pair of safety shoes must be marked clearly and durably with the following information, for example by stamping or embossing:
a) size
b) the manufacturer's trademark
c) the manufacturer's type designation
d) date of manufacture and indication of the quarter at least
e) the number of the European Standard, i.e. EN ISO 20345: 20 . .
f) symbols for the respective protective function or, if required, the corresponding category (SB, S1 ... S5)