HEAT AND FLAME

» EN ISO 11612        » EN ISO 14116         » LOI-VALUE

EN ISO 11612
Protective clothing to protect against heat and flame 

This standard specifies PPE Clothing when working where there is a risk that the garments will come into contact with heat and flame and it is the base level of protection for all Tranemo FR garments. For full body protection, the protective clothing system shall cover neck, torso, arms and legs with a single garment (a boilersuit) or a two-piece garment system (combination of jacket and trousers certified with the same level). Even an accessory, for example welding protection such as aprons and sleeve protection, can be certified for EN ISO 11612 if tested and used together with other full-coverage garments with the same certification.

The standard is divided into different categories, where the code letters show which heat and flame requirements the garment needs to fulfill. At least two categories must be tested to be able to CE mark the garments. Code letter A1 or A1+A2 plus at least one other code letter (B, C, D, E or F) is mandatory and the result is included on the CE label, together with this symbol. The code letters are classified in different levels, where the highest number is the highest tested level. The design of the garment is also a parameter in the CE marking for heat and flame garments. FR garments certified according to EN ISO 11612 B3, C2-C4, D2-D3, E2-E3 and F3 come under PPE Regulation Category III.

Code letter B indicates the fabric’s ability to block convective heat and code letter C indicates the fabric’s ability to block radiant heat. When the fabric is tested for convective heat (B) and radiant heat (C) you get two values. The first value is the time it takes for the skin temperature underneath the fabric to increase by 12°C (skin temperature approximately 47-49°C), this is when you sense the heat. The second value is the time it takes for the skin temperature to increase by 24°C (skin temperature approximately 59-61°C), this is when you risk a second-degree burn. The time for the temperature to increase from 12ºC to 24ºC is the time you have to react and move away from the heat source. Tranemo usually recommend level B1 because that allows the user to react and move away from the heat source. In metallurgy, you have to protect from radiant heat to avoid heat stress. Test result C1, gives you a reaction time of 7-20 seconds. To reach C2 you need 2 or 3 layers of garments which increase the reaction time to 20-50 seconds i.e. it increases the protection for the radiant heat from the source. 

If the fabric can resist molten aluminum it will normally also be acceptable against molten aluminum bronze and molten minerals. If the fabric can resist molten iron, it will normally be acceptable against molten copper, molten phosphor bronze and molten brass. If working with other molten metals or alloys than aluminum (D) or iron (E), please contact us and we will discuss the best fabric / garment solution for your risk assessment. Through fabric tests together with different customers, Tranemo has developed the Magma, Cantex and now also the Apex fabric.

The American Standard for protection against heat and flame is called NFPA 2112 and is more focused on flash fire risk and off-shore work rather than towards heavy industry like the European standard - which includes tests on molten metals. The biggest difference in the American Standard is the Char Length test (vertical test ASTM D64B) that is done after 100 washes and also the Flash Fire test (Manikin test ASTM F1930). The European Standard has an optional Manikin test (ISO 13506) that can be performed if you want to test the whole garment system against flash fire. EN ISO 11612 is an international standard which is also approved by the US, in this standard the tests are performed after a minimum of 5 washes.

EN ISO 14116
Protective clothing with lower level of Flame Retardant protection

The standard is often used for PPE clothing and accessories with lower level Flame Retardant protection, such as High-Visibility vests, rainwear and socks.

It is divided into three classes, where index 3 is the highest level. Index 3 garments should be worn in combination with EN ISO 11612 garments. (It is important to note that Index 1 garments should not be worn next to the skin.) This standard does not have a dedicated Symbol/Pictogram. Tranemo uses the flame symbol to indicate it is a FR garment/FR accessories.

LOI - Limited Oxygen Index

LOI means the minimum concentration of oxygen (expressed as a percentage) that would be required to support combustion of a fabric. It determines the protection of the garment regarding relative flammability and should be over 25%.

Tranemo test the LOI value on our fabrics and show this on the outside FR label. The LOI value is one way to indicate the level of FR protection a garment provides and it makes it easier for the user to compare and choose the right level of protection. LOI level depends on the FR fibre/fibre combination and the fabric weight. Tranemo does flame tests on every batch before production to ensure the high level of protection that we expect on all our fabrics is consistent.