Combustible Dust Testing

Laboratory testing to quantify dust explosion and reactivity hazards

Safety Data Sheets

Develop critical safety data for inclusion in SDS documents

Gas and Vapor

Laboratory testing to quantify explosion hazards for vapor and gas mixtures

Classification of hazardous materials subject to shipping and storage regulations
Testing and consulting on the explosion risks associated with devices and processes which use or produce hydrogen
Safety Data Sheets

Develop critical safety data for inclusion in SDS documents

Thermal Stability

Safe storage or processing requires an understanding of the possible hazards associated with sensitivity to variations in temperature

Adiabatic Calorimetry
Data demonstrate the consequences of process upsets, such as failed equipment or improper procedures, and guide mitigation strategies including Emergency Relief System (ERS) design
Reaction Calorimetry
Data yield heat and gas removal requirements to control the desired process chemistry
Battery Safety

Testing to support safe design of batteries and electrical power backup facilities particularly to satisfy UL9540a ed.4

Safety Data Sheets

Develop critical safety data for inclusion in SDS documents

Cable Testing
Evaluate electrical cables to demonstrate reliability and identify defects or degradation
Equipment Qualification (EQ)
Testing and analysis to ensure that critical equipment will operate under adverse environmental conditions
Water Hammer
Analysis and testing to identify and prevent unwanted hydraulic pressure transients in process piping
Acoustic Vibration
Identify and eliminate potential sources of unwanted vibration in piping and structural systems
Gas & Air Intrusion
Analysis and testing to identify and prevent intrusion of gas or air in piping systems
ISO/IEC 17025:2017

Fauske & Associates fulfills the requirements of ISO/IEC 17025:2017 in the field of Testing

ISO 9001:2015
Fauske & Associates fulfills the requirements of ISO 9001:2015
Dust Hazards Analysis
Evaluate your process to identify combustible dust hazards and perform dust explosion testing
On-Site Risk Management
On-site safety studies can help identify explosibility and chemical reaction hazards so that appropriate testing, simulations, or calculations are identified to support safe scale up
DIERS Methodology
Design emergency pressure relief systems to mitigate the consequences of unwanted chemical reactivity and account for two-phase flow using the right tools and methods
Deflagrations (Dust/Vapor/Gas)

Properly size pressure relief vents to protect your processes from dust, vapor, and gas explosions

Effluent Handling

Pressure relief sizing is just the first step and it is critical to safely handle the effluent discharge from an overpressure event

FATE™ & Facility Modeling

FATE (Facility Flow, Aerosol, Thermal, and Explosion) is a flexible, fast-running code developed and maintained by Fauske and Associates under an ASME NQA-1 compliant QA program.

Mechanical, Piping, and Electrical
Engineering and testing to support safe plant operations and develop solutions to problems in heat transfer, fluid, flow, and electric power systems
Hydrogen Safety
Testing and consulting on the explosion risks associated with devices and processes which use or produce hydrogen
Thermal Hydraulics
Testing and analysis to ensure that critical equipment will operate under adverse environmental conditions
Nuclear Safety
Our Nuclear Services Group is recognized for comprehensive evaluations to help commercial nuclear power plants operate efficiently and stay compliant
Radioactive Waste
Safety analysis to underpin decomissioning process at facilities which have produced or used radioactive nuclear materials
Adiabatic Safety Calorimeters (ARSST and VSP2)

Low thermal inertial adiabatic calorimeters specially designed to provide directly scalable data that are critical to safe process design

Other Lab Equipment and Parts for the DSC/ARC/ARSST/VSP2 Calorimeters

Products and equipment for the process safety or process development laboratory


Software for emergency relief system design to ensure safe processing of reactive chemicals, including consideration of two-phase flow and runaway chemical reactions


Facility modeling software mechanistically tracks transport of heat, gasses, vapors, and aerosols for safety analysis of multi-room facilities


Our highly experienced team keeps you up-to-date on the latest process safety developments.

Process Safety Newsletter

Stay informed with our quarterly Process Safety Newsletters sharing topical articles and practical advice.


With over 40 years of industry expertise, we have a wealth of process safety knowledge to share.

Recent Posts

Reaction or Adiabatic Calorimetry?

Posted by Fauske & Associates on 11.27.19

By: Donald J. Knoechel, Ph.D. , Senior Consulting Engineer & R. Gabriel (Gabe) Wood, Manager, Thermal Hazards Testing and Consulting, Fauske & Associates, LLC 

When gathering process safety information on an existing chemical process or for developing a new chemical process, the technique to choose and type of experiment to run is highly dependent on what is the intended use of the data. In this article we highlight important differences between the data from reaction calorimetry and adiabatic calorimetry and how best to use it.

Mettler Toledo RC1

The reaction calorimeters in the FAI toolbox are the Mettler-Toledo RC1, ChemiSens CPA202, and the Thermal Hazards Technology υRC. The adiabatic calorimeters are the Vent Sizing Package (VSP2), Advanced Reactive System Screening Tool (ARSST) and Accelerated Rate Calorimeter (ARC).

First and foremost, reaction calorimetry (μRC) seeks to quantify the heat evolved and the rate of heat evolution from a chemical process reaction under desired reaction conditions. Adiabatic calorimetry (AC) by definition does not hold the reaction conditions (temperature) constant and generally is used to explore the undesired runaway scenario (loss of cooling, overcharging, heating by external fire). The overlap between adiabatic calorimetry and reaction calorimetry lies in the fact that the adiabatic experiment often but not exclusively has the desired reaction as the trigger for runaway.

In contrast, the reaction calorimetry experiment maintains temperature control to stay within a predefined temperature range where primarily only the desired chemistry takes place.

The adiabatic temperature rise (ΔΤad) is a deliverable from either reaction calorimetry or adiabatic calorimetry but differs in its origin and meaning depending on which technique was used.

ChemieSens CPA 202.jpgReaction calorimetry measures the heat evolved under a predefined set of reaction conditions (often isothermal but not necessarily) and calculates an adiabatic temperature rise from the total heat, the mass and the heat capacity (also measured in a RC experiment). The total heat can be normalized to mass or moles of limiting reagent to afford a heat of reaction.

Adiabatic calorimetry measures the temperature rise as a direct consequence of the experiment though the measured value is often further corrected by heat absorbed by the test cell (via the Φ - factor) to project the true adiabatic value. Knowing the mass and a heat capacity allows the calculation of the total heat that caused the temperature rise and normalizing this by mass or moles of limiting reagent yields a heat of reaction.

It is important to realize that the adiabatic temperature rise projection from reaction calorimetry only allows for heat from the desired reaction to contribute to the temperature rise (if any). Consequently, it does not represent the entire runaway scenario but only a minimum possible value.

This calculated temperature rise from RC differs from what is measured in adiabatic calorimetry. During the adiabatic experiment further reactions may be initiated (with their own heat of reaction) when the actual rise in temperature is experienced which may contribute to a further increase in temperature (and pressure) until all reacting/decomposing components are consumed.

μRC.jpgNote also that the adiabatic potential projection from reaction calorimetry is based on the heat capacity at the desired reaction temperature where the adiabatic experiment experiences the temperature rise over the actual range in temperature and the corresponding real change in reaction mass heat capacity with temperature.

As heat capacity generally increases with temperature, the from RC is usually an overestimate of what the real temperature rise would be when only the desired reaction is involved.

The primary use for reaction calorimetry data is for purposes of heat rate scale up. That is projecting the cooling capacity required for running the process in larger equipment, from lab to kilolab to pilot plant to full-scale plant in order to maintain the desired temperature control.

RC also provides a unique window into the trajectory of the reaction. Issues encountered when considering RC data include the following: does the way the process is carried out (batch versus semi-batch) need to be changed with scale? Does an addition time need to be longer at larger scale? If so, is product of the same impurity profile produced with the longer addition time compared to that from the smaller scale (shorter add time).

Do transient solids formation present a mixing challenge and might that change with a longer addition time? Does reversing the addition alleviate those concerns? Do any changes in heat flow (or vent flow or pH, also) correspond to points of stoichiometric equivalency?

The projected ΔΤad value from RC best serves in a screening role. A process that projects low adiabatic potential from RC may be deemed safe as long as there is complimentary thermal screening results, Differential Scanning Calorimetry (DSC), for instance, indicating minimal to no thermal activity at higher temperatures from a scan of a post-reaction mixture. On the other hand, any projected temperature rise which threatens the boiling point of the reaction mass, an understanding as to whether the reaction mass could temper the runaway would require an open adiabatic test to confirm.

A potential temperature rise that could go well beyond the boiling point of the reaction mass deserves a closed adiabatic test to see how high the temperature and pressure might get and what other reactions if any might be encountered.

Fauske & Associates, LLC VSP2.jpgUltimately the purpose of an adiabatic test is to gather data on temperature and pressure rise (and rates thereof) for the runaway scenario. Low Φ - factor adiabatic calorimetry (ARSST, VSP2) is ideal for direct scaling up of the data. The low Φ - factor test minimizes the correction needed for heat loss to the test cell maximizing the quality of the data collected over the temperature rise by more closely simulating the thermal inertia of the large scale process vessel. Typically this type of data is desired when the process scale is known and design of the vent for a particular reactor configuration is requested.

ARSST are used in a screening capacity to quickly probe different scenarios. However, ARC and ARSST are used in a screening capacity to quickly probe different scenarios. ARC is more commonly used with pure materials to probe decomposition kinetics for storage and stability concerns. ARSST is better equipped to handle mixtures and to capture data while adding reagents at the process temperature.

Fauske & Associates, LLC maintains a toolbox and the expertise to characterize your chemical processes with reaction calorimentry, adiabatic calorimetry or both as needed supported by thermal screening techniques, as well. If you have process scale up or safety concerns that suggests reaction calorimetry, please contact Don Knoechel at or 630-887-5251 to discuss your process. If you have vent sizing or other adiabatic testing or thermal screening needs, please contact Gabe Wood at 630-887-5270 or email at

FAI Process Safety Newsletter



Topics: ARSST, VSP2, Reaction Calorimetry, Adiabatic Calorimetry, Reactive Chemicals


Is My Dust Combustible?

A Flowchart To Help You Decide
Download Now