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In industry the use of shoes with toe protection have a long history of protecting workers from the dangers of mechanical impacts. As one of the first producers of such shoes, Germany has more than 100 years of tradition in this area.
Legal foundations and standardisation
The legal foundation for the market of Personal Protective Equipment (PPE) in the European Community is the EU Directive 89/686 ‘on the approximation of the laws of the Member States relating to personal protective equipment’, which is published in the official journal of European communities (latest changes 1993). For all PPE the conformity to the EU Guideline is necessary. Depending on the protection against different risks, three categories of PPE are described in the Guideline with different procedures to get the CE Mark, which shows the conformity to the EU Guideline.
You can find the EU Guideline at:
http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:31989L0686:EN:HTML
Category 1: simple PPE with protection against minimal risks (e.g. gloves for gardening work)
Category 2: PPE with protection against normal risks (e.g. protective gloves, protective clothing)
Category 3: complex PPE with protection against risks of mortal or seriously injuries (e.g. PPE with protection against fall from height, PPE for fire fighting)
For category 1 PPE the conformity to the Guideline is only the responsibility of the manufacturer or his representative. For PPE of Category 2 and 3 a ‘type examination’ by a notified Body (designated by the national legislative for the conformity assessment) is necessary. For Category 2 PPE the conformity of the manufactured PPE is the responsibility of the manufacturer, for Category 3 PPE the manufactured PPE has to undergo an EC quality control system for the final products.
You can find a list of the notified bodies at Nando database:
http://ec.europa.eu/enterprise/newapproach/nando/
The CEN Technical Committee (TC) 161 for foot and leg protection with different working groups established the standards EN 344, 345, 346 and 347 – the first European standards for safety, protective and occupational footwear which were published in 1992. In the meantime these standards have been developed to EN ISO 20344-20347 and several additional standards for special footwear are also valid. Table 1 gives an overview about the actual standards for foot and leg protection.
EN ISO 20344-20347 an overview
The basic standards are the EN ISO 20344 – EN ISO 20347 in which three different shoe types are defined which are mostly separated by the toe protection, which is related to one of the most important particular risks for footwear described in Annex II of the EU Guideline:
All test methods are described in EN ISO 20344 whereas the general topics, requirements, descriptions and the marking are given in the appropriate product standard EN ISO 20345-20347.
Safety footwear (EN ISO 20345) is equipped with a toe cap and has to pass the requirements when the shoes are tested for the impact and compression tests of the toe region with higher loads. Protective footwear (EN ISO 20346) is equipped with a toe cap and has to pass the requirements for the impact and compression tests of the toe region when tested with the lower loads. Occupational footwear (EN ISO 20347) doesn’t need a toe cap; there are no requirements for the impact and compression tests.
In the standards for safety protective and occupational footwear, two classes for footwear are described (Table 2).
Regarding the risks described in Annex II of the EU Guideline, the most important or common risks were covered by the Basic Requirements (Tables 3 and 4) of EN ISO 20345, which are related to the whole piece of footwear, as well as to the materials it’s made from. Further the explanations are based on the EN ISO 20345, which is the most important and most common type of foot and leg protecting PPE.
Basic Requirements of EN ISO 20345 for the complete footwear are listed in Table 3. In the standard, different designs from low shoes (design A), ankle boot (design B) to knee height boot (design D), the requirements for the height of upper are described.
For the toe protection the most important tests are the impact test and the compression test. At the impact test (regarding EN ISO 20344, 5.4), the front part of the safety shoe is tested with an impact energy of 200 J (100 J for protective shoes), which is generated by the free falling of an anvil with a weight of 20 kg from a height of 1m (0.5m for protective shoes).
During the moment of the impact the free space in the shoe at the toe area is detected by a clay cylinder.
For the compression test, the front part of the shoe is placed between two steel plates which compress the shoe up to a force of 15.000 N (10.000 N for protective shoes). The remaining space under the toe cap is also detected by the clay cylinder.
In both tests the requirement for height of the clay cylinder – which represents the remaining space for the front part of the foot – depends on the shoe size and ranges between 12.5mm and 15.0mm.
As far as specific ergonomic features are concerned, wear trials under different conditions which simulate typical tasks of general safety footwear have to be done.
The slip resistances of the shoes are tested by generating the coefficient of friction of the whole shoes in flat and heel mode on one or two defined surfaces. A moderate slip resistant surface is generated by a tile which is wetted by an aqueous detergent solution. A very slow slip resistant surface is generated by a steel plate which is covered by glycerol.
In the real use of shoes, the safety against slip accidents was strongly influenced by the shoes, the floor, materials on the floor (such as liquids and dust), and also by the user, so the tested slip resistance is not general slip resistance for all conditions.
Also, for the materials which are used for the safety shoes, different basic requirements (see Table 4) are necessary to approve the basic health and safety requirements of the EU Guideline.
Some of these requirements are important for the stability of the shoes (e.g. strength, flexing resistance, abrasion resistance), some for good comfort (e.g. water vapour permeability, water absorption) and others for the innocuousness of the products (e.g. pH value, chromium VI).
In the standard EN ISO 20345, additional requirements are given, which can be necessary depending upon the risks to be encountered in the workplace. The most important and common additional properties for whole safety shoes are the?energy absorption, the antistatic properties and the penetration resistance.
The requirement for energy absorption should prevent the user against calcaneous (heel bone) brakes in case of sudden or unforeseeable falls from low heights. Here the heel area of the shoe is compressed with a load of 1500 N and the energy absorption of the heel region should be more than 20 J.
Regarding the requirements for the electrical properties of safety footwear, the antistatic footwear is the most important. These shoes should have an electrical resistance in a dry and wet conditioning between 100 kOhm and 1000 MOhm (1*105-1*109 Ohm), which protects the user both against electrostatic charges and the risk of by contact with low electrical currency.
The conductive footwear is very infrequent for the use of these shoes e.g. in Germany high restrictions on the electrical environment conditions are given.
The isolating footwear is also very infrequent, e.g. in Germany for working under low electrical currency the shoes have to fulfil the EN 50321.
To protect the user against nail penetration, the shoes are tested by a standardised nail with a load of 1100 N (~ 110 kg). Under this condition the nail should not penetrate the shoe. Also restrictions about the dimensions and construction of the penetration resistant insert are valid. Regarding water resistance of normal shoes (Code I of table 2), two different possibilities are given. The water resistance of the upper (WRU) describes only the water resistance of the upper materials and should lead to protect the use against water spotting and rain. The water resistance of the whole shoe (WR) should protect the user against wet conditions like walking short distances in water or wet grass.
Safety Shoes according to EN ISO 20345 have to comply with all basic requirements of the standard and the marked additional requirements.
For easy marking, six different categories of safety footwear are generated, which represent the most widely used basic and additional requirements (Table 5).
For the certification of safety shoes regarding the EU Guideline, further regulations are necessary. Important for the end user of the safety shoes is the marking of the shoes, which has to include at least the CE Mark, the size, the manufacturer’s mark, the manufacturer’s type designation, the manufacturing date (at least year and quarter) and the number and year of the standard (e.g. EN ISO 20345:2007), including the appropriate additional requirements and/or the marking category given in Table 5.
Also, an information brochure for the user is mandatory and must include the following general information:
• Name and full address of the manufacturer or his representative in the EU
• Notified body involved in the type examination
• Number and year of the standard
• Explanation of any pictogram, marking, level of performance
• Instructions of use withtests to be carried out by the wearer before use, if required fitting (how to put on and take off the footwear, if relevant) application (basic information on possible uses and, where detailed information is given, the source) limitation of use (e.g. temperature range)instructions for storage and maintenanceinstructions for cleaning and/or decontaminationobsolescence deadline or period of obsolescenceif appropriate warning against problems likely to be encountered (modifications can invalidate the type approval e.g. orthopaedic footwear) if helpful, additional illustrations, part numbers etc
• Reference to accessories and spare parts, if relevant
• The type of packaging suitable for transport, if relevant
The detailed information text regarding EN ISO 20345 8.2 is also mandatory in the brochure, if the shoes are marked with any electrical properties. Remarks regarding the use of insocks in the shoes have to be included.
Special purpose standards
In 1996 the range of standards EN 344-347 was extended by additional standards EN 344-2 to EN 347-2, which related to additional test methods requirements and specifications especially for risks of chain saw cuttings and fire fighting. During the process of revision of the standards for foot and leg protection, it was decided to generate separate standards for special purpose footwear with a different standard numbering.
In 2004 the EN ISO 17249 Safety footwear with resistance to chain saw cutting was published, with the actual version valid since 2007. In this standard most test methods and requirements refer the standards EN ISO 20344 and EN ISO 20345 and only some additional requirements and test methods are described.
The shoes according to EN ISO 17249 have to be at least a half knee boot (Design C of EN ISO 20345) and the protection area of the chain saw resistant material is defined. The test for the resistance against chain saw cutting is done in accordance with the test method in EN 381-3 and the shoe can reach four?protection levels, depending on the speed of the chain saw where no cut through occurs.
Shoes regarding to EN ISO 17249 should have an additional pictogram for chain saw including the level of protection.
For fire fighting boots the EN 15090: 2006 is the harmonized standard, which refers also to test methods of EN ISO 20344 and requirements of EN ISO 20345.
In the EN 15090 three types of footwear are described:
Type 1: general purpose rescue and fire suppression in wildlife conditions e.g. forests, farmland
Type 2: rescue, fire suppression and property conservation in buildings and enclosed structures
Type 3: for contact with hazardous emergencies with chemical risks
In Germany and most northern countries of EU the fire fighters are only allowed to use at least Type 2 footwear.
For the most common type F2A are in addition to the basic requirements of EN 20345 some additional requirements (e.g. Energy absorption (E), water resistance of the whole shoe (WR), and Heat resistant outsole (HRO) are now mandatory. Further requirements and test methods are given in the EN 15090, the most important being the flame test, the resistance against radiant heat and the heat insulation test.
During the flame test for the whole shoe, all the outer materials are exposed to a standardised flame for a period of 10 s. After this there should be no burning or glowing for more than 2 s and the material should have no serious damage.
For the radiant heat test, the complete shoe upper with all inner and intermediate materials is exposed to a standardised radiation of 20 kW/m². During this radiation the temperature of a calorimeter at the backside of the material is measured. The temperature increase of the calorimeter of 24°C should not be reached before 40 s (RHTI > 40 s), and after the radiation the materials should also have no serious damage.
For the test of insulation against heat, the shoes are placed on a hot plate in a sand bath. Three conditions and requirements are described in the EN 15090.
If the samples pass all the requirements of EN 15090 and also a EC quality control system for the final product according to article 11 of the EU guideline, a CE type examination certificate can be generated.
Perspectives in standardisation
Based on need, changes and developments in technologies, a standardisation is never finished, so the standardisation process is still running in generations of new, special purpose standards and also revising existing standards.
At the moment, the revision of the basic standards EN ISO 20344-20347 is nearly finished. The new standards will be sent to the last formal vote at the end of 2010, so if they pass this enquiry the new versions of the standards will be published in 2011.
Also, the standard for footwear for firefighting EN 15090 is in the revision phase, and if no problems occur in the enquiry process a new version will also be valid in 2011.
A new standard project is also in the last stage for the EN ISO 20349 ‘Personal protective equipment – Footwear protecting against molten metal splash – requirements and test methods’, which will be published this year, or at the beginning of 2011.
Author:
Dr Markus Scherer
After studying chemistry, graduating and additionally studying physics at the University Saarbrücken, Dr Scherer entered PFI in 1996, initially in the Chemical Laboratory. From 1997 he was head of the physical testing laboratory and since 2010 has been based at the certification department for Personal Protective Equipment. Since 1997 he has been a member of many different national and international standardisation committees for Personal Protective Equipment.
PFI was founded in 1956 in the German shoe metropolis Pirmasens. Originally dedicated to footwear-related research, the Institute has meanwhile become an internationally active organisation, with subsidiaries in Turkey and in Hong Kong, serving clients from many different industries.
Today PFI’s main focus is on testing, analytical chemistry, microbiological studies, biotechnology, certification of product and systems, testing equipment and special machinery, and software development.
With a current staff of 100 scientists, technicians, and laboratory personnel, PFI serves clients in industry, commerce, government agencies, consumer organisations, and insurance companies. We provide publicly certified experts for numerous areas of activity.
With a long history in the certification of personal protective equipment – PFI was one of the first German Bodies which was allowed to generate GS Certification for safety footwear – PFI is a notified body for PPE in foot and leg protection since the beginning of the European Certification. PFI experts worked and still work in several national and international standardisation committees on developing the standards.
Published: 10th Jul 2010 in Health and Safety International
