Protective clothing – Electrostatic properties - Part 5: performance requirements
Antistatic clothing suppresses static charge, thereby preventing sparks, which might cause a fire or explosions. EN 1149-5 is part of a larger system.
EN 1149 consists of the following parts:
- EN1149-1: test methods for the measurement of surface resistance
- EN1149-2: test methods for the measurement of the electrical resistance through a material (vertical resistance)
- EN1149-3: test methods for the measurement of charge decay
- EN1149-4: garment test method (standard currently under development)
- EN1149-5: performance requirements.
The contents of this standard
This standard’s pictogram is a lightning bolt placed above the text NEN EN 1149-5. This standard specifies requirements for clothing that conducts electricity. This clothing (combined with e.g. shoes that conduct electricity) forms part of a completely earthed system. The clothing prevents sparks and therefore explosions.
Clothing made to this standard is only accepted in combination with the standard for flame retardant clothing (531 or 11612). This clothing is worn in explosion-hazard environments - if there is a risk of explosion, there is also a risk of fire. This clothing may not be worn in oxygen-enriched environments. It does not provide protection against electric shocks (mains voltage). EN 1149-5 compliant clothing is frequently used by companies that have to adhere to the ATEX guidelines.
The fabric from which the clothing is made must be EN 1149-1, EN 1149-2 or EN 1149-3 compliant - or entire garments must be tested in accordance with EN 1149-4 (under development). Van Puijenbroek Textiel only works with materials that are EN 1149-1 or EN 1149-3 compliant.
EN 1149-1: Protective clothing - Electrostatic properties, part 1
The fabric releases its electrostatic charge via conduction. In the related test, the surface resistance is determined; it has to be ≤ 2,5 * 109 Ω. Electricity can be conducted via homogeneous or heterogeneous material. If the material is heterogeneous, static electricity has to be released via a grid of conductive fibres (metal/carbon) measuring max. 10 mm x 10 mm.
EN 1149-3: Protective clothing - Electrostatic properties, part 3
The fabric releases its electrostatic charge to the air (and not via conduction). The standard contains a test method in which the amount of time it takes for a static electrical charge to dissipate is measured (Electrostatic Discharge of clothing): t50% < 4 s or S > 0.2.
The requirements set in this standard
- Models must meet the requirements specified in EN 340
- Materials that can carry an electric charge (metal buttons, etc.) must be covered on the outside
- Non-conductive elements (reflective strips, emblems, etc.) are permitted, provided they are permanently attached. For example, a removable badge is therefore not permitted
- Clothing that complies with EN 1149-5 is in itself insufficient; the wearer must also wear shoes that conduct electricity
- The outer material must always be in contact with the wearer's skin. When designing, for example, winter clothing, the seam must therefore be in contact with the skin
- If clothing meets the requirements for EN 1149-5, it must also meet the requirements for EN 531.
ATEX is a guideline, not a clothing standard
The ATEX guideline has been drawn up for businesses where there is a risk of explosion. Examples are companies that work with chemicals, but also companies that work with flour. This directive includes all types of requirements that companies must comply with, equipment that needs to be used in these areas, the installation of the equipment, the security of areas, the protection of employees, etc.
The ATEX directive also discusses personal protection equipment, which includes clothing among other things. Clothing certified according to the EN 1149 standard complies with the requirements of the ATEX directive.