Mexico Safety Footwear Standard NOM-113-STP – 2009

For basic safety boot – Consider as ASTM plus Upper material requirements set out below

For additional EH protection – consider same as ASTM EH

For Metatarsal – Consider as ASTM plus Upper material requirements set out below

For additional Conductive, Antistatic and Penetration resistance consider as per CE marked (EN ISO requirements

General

This standard covers 7 classes of Personal Protective Footwear

• Type I Occupational footwear soft toe

• Type II Footwear with protective toecap

• Type III Footwear with electrical shock protection

• Type IV Footwear with metatarsal protection must also provide Type II protection

• Type V Footwear with conductive electrical protection

• Type VI Footwear with penetration resistant protection

• Type VII Footwear with antistatic protection

Upper materials

Tear strength – minimum 100 N. This is a regular WTM162 test.

Water absorption – minimum 35% when the material is untreated (non WP) leather. This test involves immersion in water for 8 hours and then placing between sheets of absorbent paper and running a 490g 30mm diameter roller over the assembly once.

Water desorption – minimum 40% when the material is untreated (non WP) leather. This test follows water absorption and involves suspending for 16 hours at 20°C/65% rh

Water vapour permeability – minimum 0.75 mg/hr.cm2 This WVP test is the same as is used for CE marked (EN ISO) safety footwear but test specimens are cut from material that has had the surface abraded rather than flexed (note, this is the original version of the EN ISO test).

pH of leather – minimum 3.2 and if less than 4 then 10x dilution test required. This test is the same as for CE marked (EN ISO) safety footwear.

Chromium content – minimum 2.5%. This is total chromium and should not be confused with Cr VI content.

Additional tests for Type II footwear

No sharp edges in toecap and must be corrosion resistant (no testing specified)

Impact resistance – Minimum clearances are defined for different sizes of footwear based on ‘cm sizing’ (21 cm min clearance 11mm ranging up to 30cm or more min clearance 14mm). The impact test is the same as is used for ASTM safety footwear.

Compression resistance – Minimum clearances as for impact test. The compression test is the same as is used for ASTM safety footwear.

Additional tests for Type III footwear (note no protective toecap has to be present)

Electrical shock resistance – maximum 1.0mA current leakage with 14kV (60Hz) applied for 60 seconds.

This test uses the old ASTM voltage, the current ASTM requirements uses 18kV and 1 mA max leakage.

Additional tests for Type IV footwear

Metatarsal impact – Minimum clearance of 25.4mm for size 27 and 24mm for size 24. This test is similar to the ASTM test only using a wax forefoot held in the footwear using a wooden waist/heel wedge.

Additional tests for Type V footwear (note no protective toecap has to be present)

Electrical resistance – max 100 kilo ohms. The test involves drying the footwear and measuring electrical resistance under applied 100V. This test is very similar to that used for CE marked (EN ISO) safety footwear.

Additional tests for Type VI footwear (note no protective toecap has to be present)

Penetration resistance – Minimum 1200N penetration resistance. This test is similar to that used for CE marked (EN ISO) safety footwear.

Additional tests for Type VII footwear (note no protective toecap has to be present)

Electrical resistance – min 100 kilo ohms, max 1 giga ohm. The test involves dry and moist preconditioning of footwear and measuring electrical resistance under applied 100V. This test is very similar to that used for CE marked (EN ISO) safety footwear.

The standard also includes sampling plans for Lot inspection and uses double sampling procedures.