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 be 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 be sufficiently insulating, in temperatures potentially as low as -50 degrees C to keep the wearer at a comfortable temperature. The clothing must be wind-resistant and should also have a degree of water vapour permeability to prevent the unacceptable build-up of moisture from perspiration inside the garment.

Clothing claiming protection against the cold, and which is to be placed on the European market, falls within the scope of the European Personal Protective Equipment Directive (Council Directive 89/686/EEC). Products are required to be submitted for third party independent testing and also require an EC 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 342:2004 Protective clothing (ensembles and garments) for protection aganst the cold.

The principal test in EN 342 uses a heated manikin to acess 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 the 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 (torso, arms, legs etc) this constant (elevated) temperature.

The total thermal 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 342:2004 include measurement of air permeability (for assessment of the water resistance of the material) which is classified using tests carried out on the garment’s least air-permeability layer. The garment’s outer fabric must also meet defined minimum criteria for tear strength. An optional test is resistance to water penetration (a hydrostatic head test), which has two performance level classifications. Clothing that claims this optional property must also be breathable and pass a test with the water vapour resistance of the complete material ensemble i.e. outer, insulation and lining.