Cold store clothing

Protective garments for cold conditions can be tested for thermal insulation, air permeability and resistance to water penetration.

Many occupations involve working in cold conditions, ranging from outdoor tasks in cold climates to indoor work in food storage freezers. Suitable clothing needs to incorporate a range of properties to enable wearers to perform their work. The clothing must be lightweight so as not to impede the wearer but it must also be sufficiently insulating, in temperatures potentially as low as -50°C, to keep the wearer at a comfortable temperature. The clothing must be wind-resistant and it should also have a degree of water vapour permeability to prevent the unacceptable build-up of moisture from perspiration inside the garment.

Clothing claimed to protect against the cold, and which is to be placed on the European market, falls within the scope of the European personal protective equipment (PPE) Regulation (EU) 2016/425. Products are required to be submitted for third party independent testing and also require an EU type-examination certificate from a Notified Body, such as SATRA, before they can be sold in Europe. To help with this process the European standards body, CEN, has published European Standard EN 342:2017 – 'Protective clothing. Ensembles and garments for protection against cold'.

The principal test in EN 342 uses a heated manikin to assess a complete garment or ensemble. The aim of this test is to determine the total thermal insulation of the garment. The manikin is first dressed in underwear specified in the standard, then dressed with the test garment. During the test the manikin is heated to, and maintained at, a specified temperature above ambient. Thermal insulation is determined from the power required to maintain the various sections of the manikin surface (such as torso, arms and legs) at this constant (elevated) temperature.

The resulting effective insulation value is used to classify the performance of the garment. It can also be used to estimate the maximum duration of wear based on the activity level of the wearer, the temperature of the environment and the insulation value of the clothing. These wear duration guidelines are given in an informative annex of the standard.

Other tests required by EN 342:2017 include measurement of air permeability (for assessment of the wind resistance of the material) which is classified using tests carried out on the garment’s least air-permeable layer.

An optional test is resistance to water penetration. Clothing claimed to deliver this optional property must also be breathable and pass a test for the water vapour resistance of the complete material ensemble – that is, outer, insulation and lining.

The standard also includes requirements for the strength of the outer fabric, dimensional stability to cleaning, coated materials flexibility (-50°C) and innoccuousness.

Clothing claiming to meet the requirements of EN 342:2017 must be marked with the pictogram detailed in figure 1. Alongside the pictogram it is necessary to display the performance recorded in the various EN 342 tests such as thermal insulation values, air permeability class and, if relevant, the resistance to water penetration classification.

Further information on SATRA's PPE certification and testing services is available at www.satra.com/ppe

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