In this edition of Technical Untangled, we will break down Flame Resistance and the European standard EN407 for heat protection. Our mission is to clarify the complexities of these standards to help you choose the appropriate solution for your needs.
What is Flame Resistance?
Flame resistance (FR) is the property of a material that enables it to resist ignition, limit flame spread and self-extinguish once the heat or flame source is removed.
Before diving deeper, it is important to distinguish between two key terms often used in this context:
● Flame Resistant (FR): This refers to materials that are designed to resist ignition and will self-extinguish when the heat source is removed. Their flame-resistant performance may come either from chemical treatments applied to the material or from the inherent chemistry of the fibres themselves.
● Inherently Flame Resistant: This describes fibres or fabric materials whose flame resistance is built into their chemical structure. Because the protection is part of the fibre itself, it does not wash out, wear off, or degrade over time under normal use
The flame resistance is evaluated using the standard test referred to the Limited Flame Spread Test. This determines how long a material can withstand exposure to a flame before it ignites, sustains burning or melts. This test forms the basis of the first performance digit in the EN407 standard, as explained below.
European EN407 Standard
EN407 is the European standard for gloves that protect against thermal risks (heat and/or fire). Gloves certified to EN407 carry a six-digit code that details their performance across six different thermal properties.
Limited Flame Spread – The glove is positioned vertically above a flame and exposed to ignition for 3 and 15 seconds. Classification is based on the length of time the material continues to burn and glow after the source of ignition is removed. The performance classification reflects the glove’s ability to resist ignition and limit flame propagation.
Contact Heat – In this test, the sample is placed on a calorimeter, and a heated cylinder is brought into contact with the material. Temperatures of 100, 250, 350 and 500°C are tested to determine the classification. The threshold time is calculated – the time it takes for the calorimeter temperature to increase by 10°C once the material is in contact with the heated cylinder. A threshold time of greater than 15 seconds demonstrates a pass for the test temperature. If a level 3 or 4 contact heat is achieved, then limited flame spread must also be tested and pass level 3 as a minimum.
Convective Heat – The glove is placed in a controlled chamber and exposed to a flame. The resistance is based on the length of time it takes to transfer heat from the flame. If a level 3 or 4 is achieved, then limited flame spread must also be tested and pass level 3 as a minimum.
Radiant Heat – The glove is exposed to a radiant heat source, and the classification is determined by how long it takes heat to transfer through the material. The test is performed on the back of the hand. For radiant heat performance levels of 3 or 4, the limited flame spread test shall be performed. The product shall reach at least level 3 in the limited flame spread test
Resistance to Small Splashes of Molten Metal – The glove is splashed with small droplets of molten metal and the number of droplets that are required to heat the glove to the specified threshold are measured. The classification is based on the average number of droplets counted across four samples. Specimen are taken from the palm and the back of the glove. For small splashes of molten metal performance levels of 3 or 4, the limited flame spread test must also be performed, achieving a minimum level 3.
Resistance to Large Quantities of Molten Metal – The glove is lined with a skin-simulated material and molten metal is poured over the glove. Once the test is complete, the liner material is assessed for any changes such as pin holing or degradation, and the classification is based on the weight of molten metal required to cause the changes to the skin-simulated material. If a drop of the molten metal is stuck to the glove or if the sample ignites, the material
fails the test. For large quantities of molten metal performance levels of 3 or 4, the limited flame spread test must also be performed, achieving a minimum of level 3.
The four performance levels range from ‘Level 1’, representing the lowest level of protection, to ‘Level 4’ being the highest.
Any gloves complying with EN407 must conform to the sizing and innocuousness requirements in EN ISO 21420 and must also be tested for EN388 tear strength achieving a minimum level 1 in this test.
Gloves with EN407 performance levels 3 and 4 must also be subjected to a removal test as per EN 659. The gloves should be manufactured so that they can be easily removed in case of an emergency.
To see how the Contact Heat Test is performed, click here to read our Understanding Contact Heat Article.
Choosing the Best Hand Protection Solution in Industry Applications
Hand protection needs vary significantly across different industrial roles, particularly concerning heat protection and mechanical risks. For instance, a professional working in the hot end of a glass manufacturing facility, where they deal with high temperatures and molten glass, requires a different level of protection than someone in the food industry who is working with hot trays and transferring items from the oven.
When selecting hand protection for a specific role, it is essential to review the standards the gloves comply with. This ensures that you can choose gloves that offer the highest levels of protection tailored to each application. Heat protection is not about guessing; it’s about verified, certified performance. By understanding Flame Resistance and the comprehensive EN407 standard, you empower your safety team to make informed decisions.
If you have any questions regarding specific safety and regulation requirements for contact heat, contact our team today. We would be happy to assist you in finding a solution that offers verifiable protection globally.