According to Article 1, Paragraph 2 of EU Directive 89/686/EEC, personal protective equipment (PPE) is generally any device or appliance intended to be worn or held by an individual for protection against one or more hazards that may place their health and safety at risk. This differentiates PPE in general from workwear and industrial garments worn by workers during working hours that do not provide special protection for the health of the wearer, that are usually also purchased by the workers and that have no special protective function, such as chefs’ hats or doctors’ coats. Even workwear that is prescribed by employers such as police uniforms, clothing for railway, aircraft and shipping personnel or personal protective equipment for road transport – insofar as they are subject to traffic regulations – is not classified as PPE according to the EU Directive.
In brief, personal protective equipment can be characterised as follows:
The PPE provides protection against the risks involved without carrying a greater risk itself
The PPE is suitable for the conditions at the workplace
The PPE meets the ergonomic and health requirements of the employee
The PPE fits the wearer
The PPE categories
PPE Category I (Low Risk)
Personal protective equipment where it is assumed that the user can assess the effectiveness of the equipment against minor risks and their effect, if they occur gradually and can be identified by the user in good time without danger. Examples of this category include clothing that protects against rain or gloves for gardening work.
PPE Category II
Personal protective equipment that cannot be classified as either category I or category III, such as high-visibility warning clothing or safety gloves that protect against mechanical risks.
PPE Category III (High Risk)
Complex personal protective equipment that is intended to protect against fatal dangers or serious and irreversible damage to health and where it must be assumed that the user cannot identify the immediate effect of the danger in good time. This category includes protective clothing and protective gloves for fire fighters.
The three PPE categories also include non-textile equipment such as knee guards, hearing protection, safety shoes, protective goggles and safety helmets. However, they are not the subject of this article.
Typical textile PPE
Depending on the application and protective function, there is a wide variety of textile PPE such as protective gloves and protective clothing. Some typical examples include:
Protective gloves, depending on their purpose of use, provide protection against mechanical risks and cutting injuries as well as chemicals, flames and viruses and have an antistatic effect.
Protective clothing protects against specific dangers such as dust, gases, electrical energy, flame, radioactive rays, heat, moisture, and so on. The material used and design are determined by the protective purpose.
Warning clothing is used for the early detection of persons during the day or night, for instance, when working in the vicinity of public roads, near rail tracks or as banksmen on construction sites.
Cold weather clothing provides the highest possible level of thermal insulation and wind proofing. A distinction is made between clothing against cool surroundings up to -5 ° C and clothing against cold from -5 ° C. The latter is called special cold-protection clothing.
Protective machine clothing is intended to prevent snagging on shafts, spindles, and so on. Sleeve and trouser leg closures are therefore tight to the body, buttons are covered and there are no external pockets.
Chemical protection clothing has to be selected based on the type, physical state (solid, fluid or gas) and concentration of the chemical in order to achieve the required protective effect.
Flame protection clothing is made from flame retardant material and at minimum provides short-term protection when contact is made with fire. It is used in metalworking shops and elsewhere.
Welding protection suits protect against burning from welding spatter when there is short-term contact with flames. They consist primarily of flame-retardant cotton or viscose, heat resistant leather or aramid fibres.
Cut resistant clothing is used in sectors such as forestry. In contact, a chainsaw chain cuts the outerfabric and collects the threads from the protective layer, which wind around the chainsaw drive wheel and block the machine within fractions of a second.
Fire-resistant clothing covers various protective aspects such as fire, heat and tear resistance as well as a high level of visibility. For instance, fire-resistant clothing offers a specific arrangement of reflective stripes so that the wearer can be identified in any kind of conceivable posture.
The following sections detail protective function and wear comfort.
Indispensable: the test of wear comfort
As well as protective functions, testing of physiological properties in the shape of wear comfort plays a significant role in the assessment of PPE. Wear comfort is especially important for acceptance because the pieces of clothing have to be worn over the course of many hours during hard physical work in the widest variety of climatic and physical conditions.
According to a study from the USA, circulatory collapse was the cause of death for 49% of fire fighters who lost their lives while on duty just a few years ago. The reason for that was the insufficient physiological function of their protective clothing.
For a long time, the emphasis was placed on protection from heat and flames in the development of PPE. Today it is clear that PPE also needs to aid physical cooling functions by effectively diverting sweat from the body.
Important aspects of wear comfort are therefore breathability and thermal insulation. These features are evaluated for textile materials with the “Skin Model” based on ISO 11092. For the evaluation, the material is placed on a heated, porous sintered metal place through which water vapour is released. The measurement is performed under specific climatic conditions.
The level of water vapour resistance is evaluated in doing so. This evaluation provides information about how much moisture the textile material can absorb and how much is released into the atmosphere. In other words, its level of breathability. In addition, the amount of heat lost on the metal plate and thus the thermal insulation is also evaluated.
Still fit after years: testing for ageing
To ensure its protective functions throughout its entire usage period, the PPE is also tested after pretreatment. That includes washing the clothing. The clothing is washed multiple times based on the manufacturer specifications (a minimum of five cycles) and then subjected to testing. In the case of clothing that protects against rainwater, the textiles are placed under mechanical stress by folding and chafing them 9000 times and then tested for water tightness. The ageing process can also be simulated for the textiles. In this case, the material to be tested is exposed to xenon light and moisture. This artificial ageing process is an additional test that interested customers can use for an expanded inspection of their products. The inspection involves evaluations of the abrasion and kinking resistance for the textile materials used as well as tearing and bursting resistance.
PPE testing in practice
A look inside the textile torture chamber
Testing facilities have a multitude of measuring devices and testing processes for checking the protective function and wear comfort of PPE. Here are some examples.
Flame protection testing
In flame protection testing, the flame from a Bunsen burner is applied to protective clothing for fire fighters (EN 469) and clothing to protect against heat and flame (ISO 11612) for ten seconds – the sample is then allowed to continue burning or smouldering for a maximum of two seconds. The test flame is applied to surfaces in new and treated condition and can also be applied on the edges.
Heat protection testing
The heat protection that a textile provides is tested in a heated cabinet. This test measures the changes to the textiles at temperatures of 180° C and/or 270° C. To do so, a measuring section is applied to the textile before the test to assess the shrinkage behaviour of the material under the influence of heat.
Testing the heat and flame resistance of protective clothing for fire fighters
The Thermo-Man is a mannequin made from an epoxy resin/fibre glass compound and equipped with 122 highly sensitive sensors that is used to test the heat and flame resistance of protective clothing for fire fighters. He wears the full clothing system during the test and is subjected to a flame of over 1000° C for eight seconds – a temperature equivalent to that of flowing lava. This simulates the dreaded surface flash; that is, extremely quick surface burning (over 100 cm/s) that does not affect the underlying structure. Due to the rapid propagation of flame, the risk of burning is very high. The measurement data can be used to assess this feature of the protective clothing for fire fighters and determine the wearer’s chances of survival.
In abrasion testing based on the Martindale method, a standard woollen fabric is rubbed against the fabric sample until at least two fibres of the material are destroyed. The cycles required to do so are determined. This test is intended to simulate the friction that occurs while wearing the clothing. The number of abrasive rubs is significantly higher for working or protective clothing than for suit trousers.
Testing of kinking resistance
The evaluation of kinking resistance involves imitating points that are subject to particular stress such as elbow or knee areas. The material is kinked, folded and compressed 9000 times in the test device. Product-specific features such as water tightness must not be lost after this cycle.
Testing of tear resistance
Another test for the durability of clothing is the evaluation of tear resistance. Here, the textiles are clamped into a tensile testing device and the force required to rip the material is measured (maximum force). In the case of further tear strength, the force required to further tear the textile at an existing incision is measured.