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05 June 2026

Flame-retardant plastics

Automotive, Medical, Plastic, Electrical, Industrial

Flame-retardant plastics are a key component in the design of technical components for industrial environments where there is a significant risk of fire or electrical hazards.

In sectors such as the automotive, electrical, medical and industrial machinery industries, simply choosing a standard polymer is not enough: it is essential to ensure controlled fire behaviour without compromising mechanical, chemical or processing properties.

What are flame-retardant plastics?

Flame-retardant plastics are polymers designed or formulated to:

  • Reduce the ease of ignition
  • Slow down the spread of flame
  • Promote self-extinguishing properties

It is important to note that they are not non-combustible materials. Under certain conditions they can burn, but their formulation significantly improves fire safety.

This behaviour can be achieved through:

  • The nature of the polymer itself (e.g. PPS, fluoropolymers)
  • The incorporation of flame-retardant additives

Their use is closely linked to standards such as UL 94 (plastic flammability standard), which are very common in injection-moulded parts with technical requirements.

Types of flame-retardant plastics for injection-moulded technical parts

In an industrial context, there are many different families of materials that can offer flame-retardant properties. The choice depends on mechanical, thermal and regulatory requirements, as well as cost.

Flame-retardant Polyamides: PA6 and PA66

Polyamides (PA6, PA66) are widely used in engineering components due to their:

  • High mechanical strength
  • Good thermal stability
  • Excellent structural performance

They are used in:

  • Electrical connectors
  • Structural supports
  • Functional components

Not all polyamides are inherently flame-retardant. To achieve classifications such as V0, they usually require:

  • Flame-retardant additives
  • Glass fibre reinforcement
  • Specific formulations

Flame-retardant Polycarbonate and PC/ABS Blends

Polycarbonate (PC) and its blends with Acrylonitrile Butadiene Styrene (ABS) offer an excellent balance between:

  • Impact resistance
  • Rigidity
  • Fire performance

They are commonly used in:

  • Technical enclosures
  • Electrical equipment
  • Electronic components

Commercial grades are available that can achieve a V0 rating, particularly in industrial plastic injection moulding processes.

Flame-retardant Polypropylene

Polypropylene (PP) can also be formulated as a flame-retardant material, although it has certain limitations:

  • It requires specific additives to improve its fire performance
  • Its flame-retardant performance is generally inferior to that of other engineering polymers

Nevertheless, it is a valid option when the following are prioritised:

  • Low cost
  • Lightweight
  • Chemical resistance

Polyphenylene sulphide PPS and high-performance plastics

PPS (polyphenylene sulphide) stands out as one of the most robust materials in demanding environments:

  • High heat resistance
  • Excellent dimensional stability
  • Very good chemical resistance

Furthermore, it can naturally achieve a V0 rating in many cases, making it an ideal solution for:

  • Critical electrical components
  • Demanding industrial applications

Fluoropolymers and specialist materials

Materials such as: ETFE (Ethylene-Tetrafluoroethylene), PTFE (Polytetrafluoroethylene) and PFA (Perfluoroalkoxy polymer) offer advanced properties such as:

  • Very high chemical resistance
  • Extreme thermal stability
  • Low friction

Their use in flame-retardant components is justified when the project requires more than just fire resistance, such as in aggressive environments or extreme conditions.

They are not standard solutions due to their cost and the complexity of processing them.

Flame-retardant systems: halogenated, halogen-free and mineral fillers

Flame-retardant properties do not always depend on the base polymer. In many cases, they are achieved through the use of additive systems.

There are three main families:

  • Halogenated (bromine, chlorine): highly effective but with environmental implications
  • Halogen-free: a growing trend due to safety concerns and regulations
  • Mineral fillers: hydroxides, intumescent compounds

When to consider halogen-free materials

Halogen-free materials are becoming increasingly important in sectors where the following are prioritised:

  • Reduction of toxic fumes
  • Lower corrosiveness during combustion
  • Compliance with environmental regulations

They are commonly used in:

  • Electronics
  • Transport
  • Critical infrastructure

Market developments have made it possible to obtain high-performance halogen-free V0 grades.

How additives affect processing and part properties

The addition of flame-retardant additives has a direct impact on:

  • Material flow (MFI) – Melt Flow Index
  • Mechanical strength
  • Surface finish
  • Dimensional stability

Furthermore, the correct dispersion of the additive is critical to ensuring fire performance.

In plastic injection moulding, this can result in:

  • Adjustments to process parameters
  • Changes to mould design
  • The need for additional technical validation

Applications of flame-retardant plastics across industrial cectors

Flame-retardant plastics are widely used in technical applications where thermal or electrical risks are a significant concern.

Electrical components, connectors and technical housings

These are one of the main areas of application due to:

  • Electrical hazards
  • The need for insulation
  • Strict regulatory requirements

They include:

  • Connectors
  • Terminals
  • Equipment enclosures

Parts for machinery, industrial equipment and control systems

In industrial settings, they are used for:

  • Protective covers
  • Brackets
  • Guides
  • Structural components 

Particularly in areas close to:

  • Heat sources
  • Electrical panels
  • Control systems

Components for automotive and mobility applications

The automotive sector requires materials with controlled fire behaviour in:

  • Interior components
  • Electrical systems
  • Batteries and electric mobility

Priority is given to striking a balance between:

  • Safety
  • Weight
  • Cost

Parts for medical, pharmaceutical and veterinary equipment

In these sectors, in addition to flame-retardant properties, the following factors are taken into account:

These are components for which documentary and technical validation is essential.

Criteria for choosing a flame-retardant plastic for an injection-moulding project

Selecting the right material requires a technical approach based on a number of factors.

Required UL 94 classification: HB, V-2, V-1, V-0, 5VB or 5VA

It is not always necessary to choose the highest classification.

The choice depends on:

  • Applicable regulations
  • The actual risk associated with the application
  • Customer requirements

Over-specifying can lead to unnecessary cost increases.

Temperature, mechanical strength and chemical resistance

Fire performance should not be the only criterion.

The following factors must be assessed:

  • Operating temperature
  • Mechanical loads
  • Exposure to chemicals
  • Environmental conditions

Part geometry, wall thickness and tolerances

The design of the part has a direct impact on:

  • Injection moulding feasibility
  • Actual flame-retardant performance
  • Achievable UL (Underwriters Laboratories) rating

Thin-walled or complex parts require special attention.

Material certification, technical data sheet and traceability

It is essential to check:

  • The material data sheet
  • The exact commercial grade
  • UL certification (if applicable)
  • Tested thickness
  • The compound supplier

This is particularly critical in regulated sectors.

Flame-retardant plastics: what a company should clarify before starting an injection-moulding project

Before starting an injection moulding project with fire performance requirements, a company should have defined the following:

  • Base material or polymer family
  • Required classification (UL 94 or others)
  • Part thickness
  • Actual conditions of use
  • Regulatory requirements
  • Validation requirements

Flame-retardant plastics are not a standard solution, but a technical decision that directly impacts the design, the process and the final cost.

Taking the right approach from the outset helps to avoid redesigns, cost overruns and validation issues in the later stages of the project.

Please contact us with your project or any queries and we will help you find the right solution.