EN ISO 11612
Heat, Flames and Fire
Back to overviewProtection against heat and flames: EN ISO 11612 standard for protective clothing
EN ISO 11612 describes the requirements for clothing that offers protection against heat and flames. This standard applies to workers who are at risk of brief contact with fire, convective heat, or radiant heat—with the exception of welders (EN ISO 11611) and firefighters (special standards). EN ISO 11612 is the successor to EN 531.
What does the standard entail?
The performance of the clothing is indicated by letters A to F (and optionally W). Each letter stands for a specific type of protection. If a letter is not listed or the class is “0,” the clothing does not offer protection against that risk.
Symbol and technical requirements of EN ISO 11612
The symbol is a flame with the letters and classes achieved underneath.
A: limited flame spread (A1 = horizontal, A2 = vertical)
B: convective heat (classes 1–3)
C: radiant heat (classes 1–4)
D: molten aluminum (classes 1–3)
E: molten iron (classes 1–3)
F: contact heat (classes 1–3)
W (optional): rain protection (according to EN 343)
Explanation of test values
A. ISO 15025 flame spread.
Indicates whether the fabric continues to burn or forms holes after 10 seconds of flame contact.
B. ISO 9151 convective heat.
Indicates how many seconds of protection the clothing provides against rising hot air.
C. ISO 6942 radiant heat.
This measures how long the fabric resists radiant heat. The higher the class, the longer the protection.
D. ISO 9185 molten aluminum.
Indicates the amount of molten aluminum the fabric can withstand without damage.
E. ISO 9185 molten iron.
Indicates the amount of molten iron the fabric can withstand without damage.
F. ISO 12127 contact heat.
The indication of how long direct contact with a hot surface can be tolerated.
W. Rain protection.
This is an option, not a mandatory indication. This letter indicates that the clothing has also been tested for rain protection. The test and classification for this follow the requirements of EN 343.
Where do you use EN ISO 11612 workwear?
This standard is intended for industries and work activities with a risk of heat and fire, such as:
- Petrochemicals and energy
- Iron and steel industry
- Machine construction and maintenance with a risk of fire or heat contact
Performance and design requirements of the standard
Clothing that complies with EN ISO 11612 must:
- Always comply with A1 or A2 and at least one of the other tests (B–F).
- Have a label stating the classes achieved.
- Cover metal parts (such as fasteners).
- Have the jacket and pants overlap (at least 20 cm).
- For protection against metal splashes (D/E):
- No cuffs on sleeves or legs
- Outside pockets with wide flaps
- Clasps with flaps, button spacing max. 15 cm
- Neck and legs fully closable
What is different about the EN ISO 11612 standard compared to the old EN 531 standard?
- Lining must be flame retardant for code A
- Flame retardancy tested up to 50 washes
- Higher requirements for seam strength (min. 225 N)
- Trimmings tested for heat and flame resistance
Learn more about EN ISO 11612: follow our training course.
Our training provides insight into the structure and application of the standard, including classifications, test methods, and relevant performance requirements for different heat sources. Suitable for companies responsible for clothing selection and use, as well as organizations that want to build internal knowledge about standards, safety, and legislation.