What Is Chemical Reactivity Testing?
Chemical reactivity testing evaluates how substances and mixtures behave when exposed to elevated temperatures and other conditions that may initiate hazardous reactions.
Certain chemicals may remain stable under normal conditions but undergo rapid decomposition, release substantial heat, or generate pressure when exposed to increased temperatures, contamination, or incompatible substances.
Without an adequate understanding of these hazards, manufacturers may be at risk of uncontrolled chemical reactions, equipment damage, and serious safety incidents.
Chemical reactivity testing helps identify:
- Thermal Instability: Conditions under which materials may begin to undergo hazardous thermal reactions.
- Exothermic Reactions: Chemical reactions that release heat and could contribute to uncontrolled temperature increases.
- Thermal Decomposition: The breakdown of materials at elevated temperatures, potentially releasing heat or hazardous products.
- Self-Heating Behavior: A material’s tendency to generate heat through chemical reactions.
- Thermal Runaway Potential: Conditions under which heat generation may exceed heat removal, causing reactions to accelerate.
- Pressure Generation: Pressure increases associated with certain decomposition or runaway reactions.
Understanding these properties is essential for identifying chemical process hazards and developing appropriate preventive and protective measures.
Our Chemical Reactivity Testing Services
Stonehouse offers three complementary thermal analysis and chemical reactivity testing methods to help characterize material behavior and identify potentially hazardous reactions.
Differential Scanning Calorimetry (DSC)
Identify Exothermic Reactions and Thermal Instability
Differential Scanning Calorimetry (DSC) measures heat flow associated with physical and chemical changes as a material is heated, cooled, or maintained at a controlled temperature.
DSC testing is commonly used as an initial screening method to identify potentially hazardous exothermic reactions, evaluate thermal stability, and detect thermal events associated with chemical decomposition.
DSC testing can help determine:
- Approximate onset temperatures of thermal events
- Exothermic and endothermic behavior
- Heat released or absorbed during reactions
- Potential thermal decomposition hazards
- The need for additional thermal hazard testing
DSC testing provides valuable information for evaluating the thermal stability of chemicals and identifying materials that may require more detailed investigation.
Applicable Standard: ASTM E537 – Standard Test Method for Thermal Stability of Chemicals by Differential Scanning Calorimetry.
Thermogravimetric Analysis (TGA)
Evaluate Thermal Decomposition and Material Stability
Thermogravimetric Analysis (TGA) measures changes in a material’s mass as a function of temperature or time under controlled atmospheric conditions.
By monitoring weight changes during heating, TGA helps identify thermal decomposition, volatilization, moisture loss, and other temperature-dependent processes.
TGA testing can help determine:
- Temperatures associated with significant mass loss
- Thermal decomposition behavior
- Moisture and volatile content
- Oxidation-related mass changes
- Residual material following thermal exposure
TGA testing is particularly useful for understanding how materials change when exposed to elevated temperatures.
When combined with DSC testing, TGA provides complementary information that can help distinguish thermal events associated with physical changes from those involving decomposition or other reactions.
Accelerating Rate Calorimetry (ARC)
Investigate Self-Heating and Thermal Runaway Hazards
Accelerating Rate Calorimetry (ARC) is a specialized testing technique used to investigate exothermic reactions, self-heating behavior, and thermal runaway under approximately adiabatic conditions.
Unlike conventional DSC testing, ARC is designed to evaluate how a material’s temperature and pressure may increase when heat generated by a chemical reaction is largely retained within the test system.
ARC testing can help determine:
- Detectable onset of self-heating
- Temperature rise rates during exothermic reactions
- Pressure generation during decomposition
- Self-heating and runaway reaction characteristics
- Time-dependent thermal behavior under approximately adiabatic conditions
ARC testing is particularly valuable for evaluating reactive chemicals, unstable intermediates, and processes where uncontrolled heat generation could result in hazardous conditions.
DSC vs. TGA vs. ARC: Which Test Do You Need?
| Testing Method | What It Measures | Primary Application |
|---|---|---|
| DSC | Heat flow | Identifies thermal events and potentially hazardous exothermic reactions |
| TGA | Mass changes | Evaluates thermal decomposition, volatilization, and material stability |
| ARC | Temperature and pressure behavior | Investigates self-heating and thermal runaway hazards |
DSC and TGA are commonly used to characterize thermal properties and identify potential stability concerns.
ARC provides more detailed information about self-heating and runaway reaction behavior, particularly when an initial assessment indicates the need for further investigation.
Depending on the material and objectives of the evaluation, one or more testing methods may be recommended.
Not sure which test you need?
Stonehouse’s process safety specialists can help determine an appropriate testing approach based on your materials, process conditions, and safety objectives.
To discuss your needs with the Stonehouse team or to arrange a complimentary technical conversation with one of our experts, please contact us at (609) 455-0001 or [email protected].
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