A Summer Guide for Aerosol Brands: How to Protect Product Quality, Stability & Performance in High-Heat Conditions*

 

It’s crucial to protect aerosol product quality, stability, and performance during high-heat conditions. This requires attention to formulation, packaging, manufacturing controls, and storage/ distribution. Throughout this article, we will explore some common principles that apply broadly to all aerosol products.

 

Understanding the Main Risks of High Temperatures

When aerosols are exposed to high temperatures (ranging from 35 – 60°C) during transport or storage, common issues include:

• Increased internal can pressure
• Propellant loss through valve leakage
• Changes in spray pattern and particle size
• Separation of emulsions or suspensions
• Active ingredient degradation
• Fragrance or solvent evaporation
• Corrosion of the can or valve components
• Caking, sedimentation, or viscosity changes
• Reduced shelf life

 

How Aztec Aerosols copes with this:

We choose thermally stable ingredients:

• Select active ingredients with proven thermal stability
• Avoid ingredients that oxidise, hydrolyse, or discolour at elevated temperatures
• Use high-temperature-stable fragrances and dyes where applicable

Add stabilizers (dependant on the product):

• Antioxidants e.g. to reduce oxidisation
• Chelating agents to control metal-catalysed degradation
• UV stabilisers if heat and sunlight exposure are expected
• Emulsion stabilisers and rheology modifiers

Optimise solvent system:

• Use solvents with appropriate boiling points
• Avoiding excessive use of highly volatile solvents that may increase pressure or alter spray performance after heat exposure

Improve suspension stability (for products containing solids):

• Optimise particle size distribution
• Use suspending agents
• Minimise sedimentation and hard packaging

 

Selecting the right propellent system

Choosing the correct propellent strongly affects high-temperature performance so we will always consider:

• Vapour pressure profile across the expected temperature range
• Compatibility with formulation and packaging
• Spray characteristics at elevated temperatures
• Balance hydrocarbon blends to achieve acceptable pressure
• Consider compressed gases where suitable
• Verify pressure remains within container design limits at maximum anticipated temperatures

Use heat-resistant packaging

Container selection:

• Use aerosol cans rated for expected pressure ranges
• Ensure compliance with ADR transportation and regulatory requirements
• All cans are leak detected prior to transportation to ensure no potential leakage

Valve and actuator components are selected, which are resistant to:

• Heat-induced deformation
• Chemical attack
• Seal shrinkage or swelling

With all critical components being considered e.g.

• Gaskets
• Valve caps
• Dip tubes
• Actuators

 

Conduct accelerated stability testing

Aztec Aerosols undertake elevated temperature storage prior to manufacturing any new product to monitor:

• Appearance
• Odour
• Colour
• Viscosity
• pH (if applicable)
• Active ingredient content
• Spray performance
• Internal pressure
• Leakage

These tests would reveal emulsion instability, valve issues, and container stress failures.

 

Protect during transportation and warehousing

Recommended storage conditions:

• Keep below the maximum specified storage temperature
• Avoid direct sunlight
• Use insulated storage if considered necessary

 

Perform a risk assessment:

A structured approach such as Failure Mode and Effects Analysis (FMEA) can identify the highest-risk areas:

Risk area          Typical heat-related failure

Formula            Separation, degradation

Propellant        Excess pressure

Valve                   Leakage

Gasket               Loss of seal

Can                     Bulging, corrosion

Distribution     Extreme temperature exposure

 

Example high-temperature qualification program

For a new aerosol product:

• Real-time stability at 25°C
• Accelerated stability at 40°C and 50°C
• Thermal cycling (e.g. 5°C ↔ 50°C)
• Pressure testing at maximum expected temperature
• Spray performance testing after aging
• Package compatibility assessment
• Transportation simulation testing

 

This approach helps ensure that the aerosol remains safe, stable, and performs consistently throughout its life and reaches the customer in the same condition as when it was manufactured.

* Please note that this should be used as a guide only, and any specific information for individual products can be obtained from Aztec Aerosol’s Health and Safety, and Technical Departments.