Fire rated sealants for increased passenger safety in public transport

Fire-Rated Sealants for Buses and Trains

Regular fire incidents and the trend towards a higher degree of material variations used in the commercial vehicle manufacturing industry led to more stringent fire protection regulations. Nowadays, all materials used in the construction of trains, buses, and coaches must comply with fire norms. Sika's specific fire sealant solutions, equipped with reduced burning behavior, comply with the most relevant global fire standards. These safety standards are EN-45545-2 and NFPA 130 for the Rail Industry and ECE R118 for the bus and coach industry.

The elastic sealant solutions for railway applications from Sika comply with these fire norms without compromising the adhesion or durability performance. Sika has supported the transportation industry by providing innovative, safe, and reliable sealant technologies for more than 40 years.


"Sika's high-performance sealing solutions and local support help the public transportation industry worldwide to produce safer vehicles."

Sika's global expertise, combined with the local technical service, provides commercial vehicle manufacturers optimal solutions for individual challenges in the industrial production of vehicles.

Sika is Your Strategic Partner for Fire Protection Sealing Applications

Passenger safety in public transport has the highest importance for operators and producers of commercial vehicles. Fire safety for railway applications and, therefore, products with good fire behavior ensure sufficient time for evacuation in a fire incident. Thus, fire norms are existing for decades.

Sika provides more than a comprehensive range of STP and urethane sealants, structural adhesives, and coatings that comply with ECE R118, NFPA 130, and EN 45545-2 standards. Our network of technical experts supports you in assessing the demands for the specific fire standard on a project base.

 Rely on Sika for technical support and the right  choice of product.

Sika Fire-Rated STP and Urethane Sealants for the Rail Industry

DIN EN 45545-2 and NFPA 130 are the relevant norms for the rail vehicle manufacturing industry. The EN norm is applied in Europe, India, and China. In contrast, North and Latin America and Japan follow the NFPA 130, and in there, the ASTM norms.

There are significant overlaps between the two norms, but the test procedures may vary to some extent. Both standards define general rules for rail vehicles intending to improve fire and passenger safety. Ultimately, the norm denotes the reduced probability for ignition of the materials used for rail vehicle construction.
It shall minimize the flame spread and therefore provide enough time for passenger evacuation. Depending on specific criteria, materials or components used in Rail are categorized.

They need to fulfill requirements "R," which ultimately boil down to a set of tests. Sika offers Sikaflex®-200 urethane sealants and Sikaflex®-500 STP sealants (silane terminated polymer) based elastic sealant solutions for all requirements and hazard levels. We offer a wide range of elastic sealing solutions, from Sikaflex®-221 to top-class product Sikaflex®-821 FR that meets the highest requirements.

Operation Category Design Category N: Standard Vehicles A: Automatic vehicles (no emergency trained staff board D: Double decked vehicles S: Sleeping and couchette cars, DD or single deck
1   HL1 HL1 HL1 HL2
2   HL2 HL2 HL2 HL2
3   HL2 HL2 HL2 HL3
4   HL3 HL3 HL3 HL3
> 0,20 m2 Interior R1
> 0,20 m2 Exterior R7
< 0,20 m2 Interior R22
≤ 0,20 m2 Exterior R23

Sika Fire-Rated Elastic Sealants for the Bus and Coach Industry

The ECE R118 standard is valid for Europe and dictates that every material used in the bus and coach construction shall not provoke the spread of fire. The norm describes the requirements and tests to determine the fire behavior.

  • All new-build buses and coaches produced in Europe must comply with the standard.   
  • Depending on their position on the bus, materials or components must comply with either annex 6 or with annexes 7&8. 


The standard requires the following tests:

  • Annex 6 describes the measurement of the horizontal burning rate.
  • Annex 7 determines melt and dripping behavior.
  • Annex 8 follows the ISO standard 5658-2, identical to the spread of flame requirement in EN 45545-2.

Sika offers high performance elastic sealants, the Sikaflex®-200 urethane sealants and the Sikaflex®-500 STP sealant range, based on Sika's own Silane Terminated Polymer (STP) technology, combines the durability of polyurethanes with sustainability and easy processing. 

Fire-Rated Sealants, Adhesives and Coatings Overview

Sika offers a wide range of products consisting of different technologies. The specific elastic sealant solutions for various applications cover the particular requirements in both markets, Bus and Coach, and the Rail manufacturing industry. The brochure shows which urethane and STP sealants carry which certificate.