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


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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

Assessing Electrostatic Hazards

Posted by Fauske & Associates on 01.15.15

By: Zach Hachmeister, Director of Operations, Fauske & Associates, LLC

Identifying the electrostatic characteristics of a material is an important step when evaluating the hazards associated with a process, especially for those that handle materials that exhibit low ignition energies.Charge separation and accumulation are inherent problems resulting from industrial operations Powder_Charge_Test_1that handle powders of low conductivity. This charge separation and accumulation is a product of the friction and impact between particles that occurs during the movement of granular material during a variety of typical process operations.To identify potential static electrical hazards of a material, it is important to evaluate the level of charge separation and accumulation that occurs during transport, the resistivity of the material and how quickly any accumulated charge can be dissipated.

Materials we refer to here include all types of flammable hazards including combustible dust/dust hazards, flammable liquid, flammable gas and flammable vapors. The prevention of dust explosions and other fire hazards are are the basis of comprehensive process safety management programs. Necessary combustible dust testing, liquid flammability testing and other flammability hazard testing are defined by the unique setting of each work environment. 

Streaming current is defined as the current generated from the flow of charged materials. The level of streaming current generated depends upon the static electricity characteristics of the material and the nature of the process. Unfortunately, there is no relationship between the streaming current in powders and that of liquids (1). In these instances, experimental determinations must be made to identify ignition hazards that may result from charge accumulation during process operations. From these types of experiments the charge density of a material can be calculated which can then be compared to typical charge densities associated with process operations. A list of charge density ranges observed during various operations that process non-conductive powders are shown below.

20130118-2ZH 1 R.A. Mancini, “The Use (and Misuse) of Bonding for Control of Static Ignition Hazards, “Plant/Operations Progress (Jan.1998) 7(1): 24. 

To identify the streaming current and charge accumulation of a material, Fauske & Associates, LLC (FAI) provides a Powder Chargeability test. The test procedure involves pouring a known amount of material down an inclined section of pipe. The powder then exits the pipe, falling into a Faraday cup. During the test, the charge that accumulates in the Faraday cup is measured using a coulomb meter and the flow rate
of the powder is recorded on a mass per time basis. This data can then be used to approximate the charge density of a material.


To further classify the powder, it is necessary to evaluate the resistivity of the material. This is done per ASTM D257. The resistivity of a powder is governed by the particle size, level of surface contamination and packing density of the material and often is quite different than the resistivity of the material in its pure solid form. Powders with high resistivities typically lose their charge very slowly, even when the process equipment is properly grounded. In some instances, this can translate to poor heat dissipation and can lead to potential fires (2). More importantly, improper handling of materials with both high and low resistivity can create hazardous scenarios. Insufficient grounding and bonding of process equipment can lead to high levels of charge accumulation. At some point, a threshold is reached and charge breakdown occurs resulting in an static electricity discharge that could potentially ignite nearby flammable vapors or combustible dusts.

At FAI, we follow ASTM D257 to evaluate the volume and surface resistivity of a material.  The volume resistivity can be determined by measuring the electrical resistance between opposite faces of a volume of powder.  The volume resistivity of the material, commonly expressed in ohm-meter, can then be used to classify the material as either a conductive, dissipative or insulative. Likewise, the surface resistivity can be characterized by slightly modifying the test procedure. The units for surface resistivity are ohms per square. The square refers to any square geometry of a material, whether it be a square meter, square foot or square centimeter. The ranges used to characterize a material based on these parameters are shown below.


Results from a resistivity test conducted on a Pittsburgh pulverized coal sample using this method are shown below.


Another important electrostatic characteristic is the charge relaxation time of powders. This property varies greatly amongst different materials and is hard to estimate even if the dielectric constant of the material is approximated because it does not follow the hyperbolic trend found in liquids. The proper method to evaluate the charge decay time of a specific powder is to directly measure it. Once an understanding of the time required for a charge to relax for a given powder is gained, process parameters such as flowrate or hold up time, can be adjusted and proper grounding and bonding of equipment can be implemented to reduce the amount of charge that accumulates during a given process.

At FAI, a JCI 155 Charge Decay Test Unit is used to measure the charge decay of powders. This piece of equipment is programmed to apply a 10 kilovolt corona charge to a powder sample which is virtually immediately exposed to a field meter after charging occurs. The field meter measures the initial charge the material received and the time it takes to relax. The decay time is reported for both the time it takes for the charge on the sample to relax to 37.9% (1/e) of its initial charge and the time it takes for the charge to reach 10% of its initial value. Below is a plot and summary of the data collected from a charge decay test conducted on a sample of Pittsburgh pulverized coal.



From the tests conducted on Pittsburgh pulverized coal, it can be seen that the material is very resistive in powder form. Processing this material will likely result in charge accumulation and could reach conditions that result in a hazardous static electricity discharge. However, by utilizing this data, it is possible to minimize this risk by implementing proper grounding and bonding of process equipment. The data also provides clues on how to adjust process parameters to reduce charge build up and ultimately help work towards creating a safe work environment.

Gaining an understanding of the electrostatic characteristics of a particular material can greatly assist in the assessment and mitigation of fire and explosion hazards in the process environment. For additional information on assessing electrostatic hazards, please contact FAI at or 630-887-5223. 


Pratt, Thomas H. Electrostatic Ignitions of Fires and Explosions. New York : American Institute of Chemical Engineers, 2000.
Britton, Laurence G. Avoiding Static Ignition Hazards in Chemical Operations

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