Fire Resistance in Vehicles: What UN Regulation 118 Requires from Manufacturers

Key data

If you manufacture vehicles, supply interior components or participate in technical approval processes, UN Regulation No. 118 affects you directly. This regulation, published in the Official Journal of the European Union on 17 March 2026 with reference CELEX:42026X0535, updates the requirements that interior materials and components of certain categories of motor vehicles must meet in terms of fire resistance and ability to repel fuel or lubricant.

The operational key is this: if a vehicle's materials do not meet the technical test and approval criteria established in this regulation, that vehicle cannot be commercialized in markets adhering to the agreement, which includes all EU Member States.

What does this regulation establish?

UN Regulation No. 118 establishes uniform provisions on two differentiated technical aspects for materials used in the manufacture of certain categories of motor vehicles:

• Behaviour on exposure to flame: interior materials must meet technical test criteria that demonstrate their resistance or behaviour in a fire situation.
• Ability to repel fuel or lubricant: certain components must demonstrate that they do not absorb or retain fuel or lubricant in a way that could increase ignition risk.

To demonstrate compliance with both requirements, the regulation defines a technical approval process that manufacturers, suppliers and certification bodies must follow. This process includes specific tests whose criteria are set out in the regulation text.

Having been incorporated into the European framework through its publication in the OJEU, the regulation ceases to be an international technical recommendation and becomes a mandatory requirement throughout the European Union.

Economic and operational impact

The impact of this regulation is not measured in a published fee or penalty figure, but in the cost of non-compliance: the inability to commercialize the vehicle. For manufacturers and suppliers, this translates into three specific operational consequences:

• Cost of material review and validation: interior materials and components currently in use must be evaluated against the new technical criteria. If they do not meet them, they must be replaced or reformulated before the vehicle can obtain approval.
• Cost of testing and certification: technical approval processes involve laboratory testing, technical documentation and the involvement of approval bodies. Each material or component that must be recertified generates a direct cost.
• Commercial blocking risk: a vehicle that does not meet the requirements of UN Regulation 118 cannot be commercialized in the EU or other markets adhering to the agreement. This risk affects both new models and those already in development or validation.

For component suppliers, the impact is also direct: if their materials do not comply, their manufacturing customers will not be able to approve the vehicle, which may result in loss of the supply contract.

Who does it affect?

• Motor vehicle manufacturers of the categories covered by the regulation, who must ensure that all interior materials of their vehicles meet the test criteria.
• Component suppliers who supply interior materials, coverings, foams, fabrics, plastics or other elements that form part of the passenger compartment or areas near sources of heat, fuel or lubricant.
• Technical approval bodies responsible for certifying vehicle and component compliance, which must apply the updated criteria of UN Regulation 118 in their evaluation processes.
• R&D, quality and approval departments of manufacturers and suppliers, which are responsible for managing technical and documentary adaptation.

Practical example

A passenger transport vehicle manufacturer that has a new model in development planned for launch in the European market must, before requesting vehicle approval, verify that all interior materials—upholstery, door panels, ceiling coverings, seat foams and plastic elements—meet the technical test criteria for fire behaviour established in UN Regulation 118.

If any of these materials is supplied by an external supplier and does not yet have certification updated in accordance with this regulation, the manufacturer has two options: require the supplier to recertify the material, or replace it with an already approved one. Either option involves time and cost before the vehicle can receive approval and be commercialized in the EU.

In the case of a component supplier that supplies seat foams to several manufacturers, reviewing their materials against the new criteria is not optional: if their products do not comply, their customers will not be able to approve the vehicles that incorporate them, with the consequent risk of loss of contracts.

What should companies do now?

1. Identify affected materials and components: review which interior materials and vehicle components are subject to UN Regulation 118 requirements, both those manufactured in-house and those supplied by third parties.
2. Assess current certification status: check whether materials in use have current approval in accordance with updated technical criteria. If certification predates the entry into force of this version of the regulation, new validation may be necessary.
3. Coordinate with component suppliers: require suppliers to provide updated documentation on their materials' compliance with UN Regulation 118. Include this requirement in supply contracts as a condition of approvability.
4. Plan necessary recertification testing: for materials that do not have updated certification, initiate the testing process with competent technical approval bodies, taking into account the timeframes these processes require.
5. Update vehicle approval technical documentation: ensure that the vehicle's technical file reflects compliance with UN Regulation 118 requirements in its current version, for approval processes before competent authorities.
6. Consult the official source to confirm the entry into force date: given that the application date is not specified in the published data, it is necessary to review the full text of the regulation in the OJEU to know the exact compliance deadlines.