Protective clothing and disposable coveralls

Our textile testing lab in Ellefeld makes sure that our safety textiles fulfil (and in most cases heavily exceed) the necessary safety standards. We explain exactly how this works in our blog series "How safe is safe": 

Part 1
Part 2

The European standard DIN EN 343 regulates the requirements for clothing to protect against rain as part of protective workwear.

This clothing is coverall against precipitation, rain, fog and wind at temperatures greater or equivalent to –5 °C. Two performance parameters are specified for this coverall:

x = water penetration resistance (water tightness)
Classification into classes 1 to 3 is possible. Class 3 has the highest water penetration resistance and fulfils the highest requirements.

Water penetration resistance (WP) is measured in pascals (Pa) and is the hydrostatic pressure held by a material. The term "water column" is often used, which is then given in millimeters. Both the material and seams are tested.

y = Water vapour resistance (breathability)
Classification into classes 1 to 3 is possible. Class 3 has the lowest water vapour resistance and fulfils the highest requirements.

Water vapour resistance (Ret) is measured in m²*Pa/W and the lower the resistance the better the breathability of the textile. If the garment has a Ret value of class 1, it must carry the warning "limited wearing time" after this number.

Standard EN ISO 20471 governs the minimum requirements for high-visibility clothing. High-visibility clothing is a visual signal of the wearer's presence – and makes the wearer conspicuous in dangerous situations, in all possible light conditions during the daytime and also in the dark when seen in headlights. Visibility is achieved by making a sharp contrast between the clothing and the background against which it is seen. Coverall therefore needs to be chosen according to the predominant background in order to ensure maximum protection. High-visibility clothing generally consists of a basic fluorescent material and a retro-reflective material. The minimum areas in square metres on the background and reflective material determine the class of high-visibility clothing. The class is indicated as a number on the right next to the pictogram as "x". High-visibility clothing is classified into three risk levels in accordance with EN ISO 20471:

• low risk = conspicuity/li>
• medium risk = increased conspicuity
• high risk = high conspicuity

DIN EN 510 describes the specifications for coverall for areas where there is a risk of entanglement in moving parts.

Duly certified coverall minimises the risk of entanglement or textiles getting caught in moving parts if the wearer is working at or near machinery or equipment with dangerous movements.

Particular properties of the clothing therefore include:

• no pockets on jackets that can be reached from the outside
• no stitched folds
• covered fasteners
• close-fitting

The following parts are combined under the main title DIN EN 1149 "Electrostatic properties": Part 1: Test method for measuring surface resistivity
Part 2: Test method for measuring vertical resistance
Part 3: Test method for measuring charge decay
Part 4: Testing clothing (standard currently in progress)
Part 5: Performance requirements for material and construction This is coverall with antistatic characteristics. This clothing reduces electrostatic charging of personnel and the occurrence of inflammable static sparks. It is required in areas where explosive atmospheres can occur. The standard defines the electrostatic requirements for clothing to avoid inflammable discharges.

Coverall for welding and allied processes in accordance with EN ISO 11611 protects the wearer from small molten metal splashes, brief contact with flames, and radiant heat from the electrical arc. The clothing can be suitable for persons during welding and allied processes where the same type and similar hazards occur. The protective effect is achieved with flame retardant fabric in conjunction with specific processing properties, which are defined in EN ISO 11611. One criterion for classification as coveralls for use in welding is limited flame spread. Testing this criterion involves analysing how the fabric burns after being exposed to a small vertical flame.

The test is based on EN ISO 15025 (formerly DIN EN 532), which specifies that:

• no sample may continue to burn to the upper or side edges
• no sample may exhibit hole formation greater than 5x5 mm²
• no sample may give off flaming or melting debris
• the mean afterflame time may not exceed 2 seconds
• the mean afterglow time may not exceed 2 seconds

Classification of coveralls into two classes

Class 1 (lower): Protection against less hazardous welding techniques and situations with a lower number of welding splashes and radiant heat; at least 15 drops of molten metal and radiant heat transfer index (RHTI) 24 ≥ 7 s

Class 2 (higher): Protection against more hazardous welding techniques and situations with many welding splashes and high radiant heat; at least 25 drops of molten metal and radiant heat transfer index (RHTI) 24 ≥ 16 s

The flame spread tests may be carried out according to two different procedures – it is also possible to test using both methods (A1+A2).

Method A – surface ignition: The flame is applied to the centre of the sample.
Method B – bottom edge ignition: The flame is applied to the bottom edge of the sample.

Coveralls with standard EN ISO 11612 – clothing to protect against heat and flames – protects workers who come into brief contact with flames and at least a type of heat. A test criterion for classification as coveralls for workers exposed to heat is the limited flame spread in accordance with EN ISO 15025 (previously DIN EN 532, in the same way as the test criterion for coveralls for use in welding (code letter A). The type of heat is defined by the codes (B to F). The heat that occurs can be convective (code letter B), radiant (code letter C), caused by molten aluminium (code letter D) or molten iron (code letter E) splashes, as contact heat (code letter F) or as a combination of these forms. In addition to the code letters, performance levels 1 to 4 are also specified for this coverall. The higher the performance levels, the higher the protective effect of the relevant item. The protective effect is achieved with flame-retardant fabric in conjunction with specific processing properties. Additional performance levels are defined for heat transfer:

• Level 1: Effect of a low risk
• Level 2: Effect of a medium risk
• Level 3: Effect of a high risk
• Exception: A level 4 applies for exposure to intense radiant heat (see code C).

Heat resistance is measured at a temperature of 180 °C (+/– 5 °C), or optionally at 260 °C (+/– 5 °C). The full clothing can be optionally tested to predict burns.

Coveralls in accordance with the DIN EN 61482-1-2 standard – Coveralls against the thermal risks of an electric arc – refers to thermal clothing. This clothing is suitable for work in the low-voltage range where thermal risks can occur because of an electric arc. An important test criterion is checking arc resistance in accordance with DIN EN 61482-1-2. The measurement is taken using the CENELEC arc box test in which energetic thermal insulation measurements and a quantitative evaluation of the burn risk are carried out. The clothing is not, however, electrically insulating coveralls in accordance with EN 50286.

DIN EN 61482-1-2 governs test methods to determine the arc rating of the material and the clothing using a directed test arc (box test).

Measurement of the thermal energy in the box test for material:

• the Stoll Curve is used to evaluate whether the transfer of heat can cause second degree burns
• evaluation of the box test for clothing, including all accessories, sewing thread and fasteners etc.

Other requirements:

• outer and inner material must fulfil Index 3 of the limited flame spread, and the inside layers Index 1.
• Use of a heat-resistant sewing thread (up to 260 °C)

If the front of the product (in the case of jackets for example) is in a higher protection class than the back, the entire front, including the sleeves, must be in this higher class. The different performance of the back must be clearly marked.

Standard DIN EN ISO 14116 specifies the performance requirements for materials, material assemblies and coverall with limited flame spread. The standard aims to prevent potential hazards from inadvertent, brief and occasional contact with small flames. This relates to situations where there are no significant risks from heat or any other heat sources.

coveralls that comply with this standard is not suitable if additional protection is needed because of a risk from heat and flames.

The standard also defines additional requirements for coveralls, including mechanical requirements and requirements governing labelling and the supply of information from the manufacturer.

 Specified model requirements for clothing in standard DIN EN ISO 14116 are:

• Sufficient overlap between jacket and trousers
• No turn-ups on trouser legs
• No flame or thermally conductive parts across all layers
• Stitch strength after five washes of more than 30 Newtons

Coveralls in accordance with EN ISO 14116 consists of several one or multi-layered garments or a single garment. Each material assembly is assigned to an index (1, 2 or 3) for limited flame spread in accordance with testing as per ISO 15025.

Standard DIN EN 14605 regulates the requirements for whole-body protective suits or full protection suits (with sealed connections between different parts of the clothing if present).

Chemical coveralls are essentially divided into categories according to specific applications. The following table describes the classifications in accordance with DIN EN 14605:

Testing requirements for coveralls in accordance with DIN EN 14605 cover:

• abrasion resistance
• flex cracking resistance
• flex cracking resistance at -30 °C
• tear resistance
• tensile strength
• puncture resistance
• resistance to permeation by liquids

The test criteria for coveralls against liquid chemicals can be proven using specific test methods.

Test methods for chemical coveralls

Jet test (used for liquid-tight protective suits – type 3)
For the jet test for liquid tight protective suits, the coverall is worn by a test person over an absorbent overall. The material undergoes predetermined stress testing while a specific volume of marker liquid is blown at the test person from a test apparatus (using a strong air stream). The liquid-tightness of the protective suit is determined via a visual inspection of the overall worn underneath.

Spray test (used for spray-tight protective suits – type 4)
The functionality of type 4 spray-tight protective suits is tested by way of a liquid spray test. The spray test is carried out in the same way as the jet test, with the difference that the marker liquid is blown from the test apparatus in bursts of finely atomised spray.

The European standard ISO 13982 regulates the minimum requirements for type 5 chemical protection suites. This covers whole-body protective suits that protect the wearer against particles and aerosols of solid chemicals.

The garments specified by the standard cover the torso, arms and legs (with or without a hood or foot protection). The particle-resistant chemical coveralls must have resistant properties against the penetration of airborne solid particles in order to adequately protect the wearer. 

Standard DIN EN 13034 relates to the minimum requirements for protective suits offering spray protection (type 6 chemical protection suits). Protective clothing in accordance with the European standard offers limited protection against the effects of liquid aerosols, sprays and light splashes in areas in which the risk of chemical exposure is considered to be relatively low.

The standard's requirements include protection provided by special finishing of the fabric in combination with the required processing of the suit, particularly the seams. Test criteria for these requirements include resistance of the material against penetration by liquids, and resistance to penetration by sprays (see spray test method).

Standard DIN EN 32781 regulates the minimum requirements for protective suits that are worn when handling or spraying pesticides and should protect the wearer from potential hazards when spreading such substances.

The performance requirements for coveralls against pesticides include regulations on the strength and impermeability of the material. The penetration is determined with a special test method in accordance with standard DIN EN 14786:2006.

Working with undiluted, concentrated pesticides also requires additional protective equipment such as aprons, special safety gloves for plant protection and face protection. 

The performance requirements and test methods for coveralls against infectious agents are regulated in standard DIN EN 14126. Coveralls tested in accordance with DIN EN 14126 guarantees resistance against the penetration of biologically contaminated liquids (wet bacterial penetration).

The special requirements for clothing materials used to protect against infectious agents guarantee protection of the skin and the wearer from potential contact with biological substances, thus helping to prevent the spread of microbes. Protective suits certified in accordance with DIN EN 14126 can be identified by the biohazard pictogram.

Standard DIN EN 14126 covers the following tests for coverall materials:

• penetration test using synthetic blood (ISO/FDIS 11603)
• resistance against viruses (ISO/FDIS 16604)
• resistance against bacteria (ISO/DIS 22610)
• resistance to penetration by biologically contaminated aerosols (ISO/DIS 22611)
• resistance against contaminated dust (ISO/DIS 22612)

Part 2 of standard DIN EN 1073 regulates the requirements and test methods for non-ventilated coveralls against particulate radioactive contamination. Coveralls in accordance with the standard should protect the wearer against radioactive contamination from solid particles.

The standard does not cover protection from ionising radiation, or protection of patients against contamination from radioactive substances used in diagnostic or therapeutic measures.

The performance requirements for the coveralls also demand that the garment is easy to put on and take off, and that the contamination risk is reduced to a minimum. The coveralls may consist of one part or of several parts that are put on together. Coveralls in accordance with DIN EN 1073-2 must also be equipped with firmly and permanently attached accessories (hood, gloves, galoshes, respiratory protection).